Add support for direct DevTools protocol messaging (fixes issue #2961).

This change allows the client to directly send and receive DevTools
protocol messages (send method calls, and receive method results and
events) without requiring a DevTools front-end or remote-debugging
session.

This change includes additional supporting changes:
- Add a new CefRequestHandler::OnDocumentAvailableInMainFrame
  callback (see issue #1454).
- Add a CefParseJSON variant that accepts a UTF8-encoded buffer.
- Add a `--devtools-protocol-log-file=<path>` command-line flag for
  logging protocol messages sent to/from the DevTools front-end
  while it is displayed. This is useful for understanding existing
  DevTools protocol usage.
- Add a new "libcef_static_unittests" executable target to support
  light-weight unit tests of libcef_static internals (e.g. without
  requiring exposure via the CEF API). Files to be unittested are
  placed in the new "libcef_static_unittested" source_set which is
  then included by both the existing libcef_static library and the
  new unittests executable target.
- Linux: Remove use_bundled_fontconfig=false, which is no longer
  required and causes unittest build errors (see issue #2424).

This change also adds a cefclient demo for configuring offline mode
using the DevTools protocol (fixes issue #245). This is controlled
by the "Offline mode" context menu option and the `--offline`
command-line switch which will launch cefclient in offline mode. When
cefclient is offline all network requests will fail with
ERR_INTERNET_DISCONNECTED and navigator.onLine will return false when
called from JavaScript in any frame. This mode is per-browser so
newly created browser windows will have the default mode. Note that
configuring offline mode in this way will not update the Network tab
UI ("Throtting" option) in a displayed DevTools front-end instance.

BUILD.gn

@@ -106,6 +106,7 @@ import("//media/media_options.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 import("//ppapi/buildflags/buildflags.gni")
 import("//printing/buildflags/buildflags.gni")
+import("//testing/test.gni")
 import("//third_party/icu/config.gni")
 import("//third_party/widevine/cdm/widevine.gni")
 import("//tools/grit/repack.gni")
@@ -262,12 +263,6 @@ if (is_clang) {
   assert(!clang_use_chrome_plugins)
 }
 
-if (is_linux) {
-  # Use system fontconfig. This avoids a startup hang on Ubuntu 16.04.4 (see
-  # issue #2424).
-  assert(!use_bundled_fontconfig)
-}
-
 if (is_mac) {
   # Always generate dSYM files. The make_distrib script will fail if
   # enable_dsyms=true is not explicitly set when is_official_build=false.
@@ -316,6 +311,7 @@ group("cef") {
   deps = [
     ":cefsimple",
     ":ceftests",
+    ":libcef_static_unittests",
   ]
 
   if (!is_linux || use_x11) {
@@ -373,6 +369,41 @@ if (is_win) {
   }
 }
 
+# libcef_static source files that have unit tests.
+source_set("libcef_static_unittested") {
+  sources = [
+    "libcef/browser/devtools/devtools_util.cc",
+    "libcef/browser/devtools/devtools_util.h",
+  ]
+
+  deps = [
+    "//base",
+  ]
+
+  configs += [
+    "libcef/features:config",
+    "//build/config:precompiled_headers",
+  ]
+}
+
+# Executable target for libcef_static unit tests.
+test("libcef_static_unittests") {
+  sources = [
+    "libcef/browser/devtools/devtools_util_unittest.cc",
+  ]
+
+  deps = [
+    ":libcef_static_unittested",
+    "//base/test:run_all_unittests",
+    "//testing/gtest",
+  ]
+
+  configs += [
+    "libcef/features:config",
+    "//build/config:precompiled_headers",
+  ]
+}
+
 static_library("libcef_static") {
   sources = includes_common +
             gypi_paths.autogen_cpp_includes + [
@@ -412,10 +443,14 @@ static_library("libcef_static") {
     "libcef/browser/context.h",
     "libcef/browser/context_menu_params_impl.cc",
     "libcef/browser/context_menu_params_impl.h",
+    "libcef/browser/devtools/devtools_controller.cc",
+    "libcef/browser/devtools/devtools_controller.h",
     "libcef/browser/devtools/devtools_file_manager.cc",
     "libcef/browser/devtools/devtools_file_manager.h",
     "libcef/browser/devtools/devtools_frontend.cc",
     "libcef/browser/devtools/devtools_frontend.h",
+    "libcef/browser/devtools/devtools_manager.cc",
+    "libcef/browser/devtools/devtools_manager.h",
     "libcef/browser/devtools/devtools_manager_delegate.cc",
     "libcef/browser/devtools/devtools_manager_delegate.h",
     "libcef/browser/download_item_impl.cc",
@@ -739,6 +774,8 @@ static_library("libcef_static") {
     ":cef_make_headers",
     ":cef_service_manifests",
 
+    ":libcef_static_unittested",
+
     # Generate API bindings for extensions.
     # TODO(cef): Enable if/when CEF exposes its own Mojo APIs. See
     # libcef/common/extensions/api/README.txt for details.

cef_paths.gypi

@@ -8,7 +8,7 @@
 # by hand. See the translator.README.txt file in the tools directory for
 # more information.
 #
-# $hash=21f0ab1e9902e4a47bf2893a4a383d33bd8161e2$
+# $hash=30eed8c81da55c640eb6a491283d1c00fb59d635$
 #
 
 {
@@ -26,6 +26,7 @@
       'include/cef_context_menu_handler.h',
       'include/cef_cookie.h',
       'include/cef_crash_util.h',
+      'include/cef_devtools_message_observer.h',
       'include/cef_dialog_handler.h',
       'include/cef_display_handler.h',
       'include/cef_dom.h',
@@ -122,6 +123,7 @@
       'include/capi/cef_context_menu_handler_capi.h',
       'include/capi/cef_cookie_capi.h',
       'include/capi/cef_crash_util_capi.h',
+      'include/capi/cef_devtools_message_observer_capi.h',
       'include/capi/cef_dialog_handler_capi.h',
       'include/capi/cef_display_handler_capi.h',
       'include/capi/cef_dom_capi.h',
@@ -260,6 +262,8 @@
       'libcef_dll/ctocpp/domvisitor_ctocpp.h',
       'libcef_dll/ctocpp/delete_cookies_callback_ctocpp.cc',
       'libcef_dll/ctocpp/delete_cookies_callback_ctocpp.h',
+      'libcef_dll/ctocpp/dev_tools_message_observer_ctocpp.cc',
+      'libcef_dll/ctocpp/dev_tools_message_observer_ctocpp.h',
       'libcef_dll/ctocpp/dialog_handler_ctocpp.cc',
       'libcef_dll/ctocpp/dialog_handler_ctocpp.h',
       'libcef_dll/cpptoc/dictionary_value_cpptoc.cc',
@@ -566,6 +570,8 @@
       'libcef_dll/cpptoc/domvisitor_cpptoc.h',
       'libcef_dll/cpptoc/delete_cookies_callback_cpptoc.cc',
       'libcef_dll/cpptoc/delete_cookies_callback_cpptoc.h',
+      'libcef_dll/cpptoc/dev_tools_message_observer_cpptoc.cc',
+      'libcef_dll/cpptoc/dev_tools_message_observer_cpptoc.h',
       'libcef_dll/cpptoc/dialog_handler_cpptoc.cc',
       'libcef_dll/cpptoc/dialog_handler_cpptoc.h',
       'libcef_dll/ctocpp/dictionary_value_ctocpp.cc',

cef_paths2.gypi

@@ -470,6 +470,7 @@
       'tests/ceftests/browser_info_map_unittest.cc',
       'tests/ceftests/command_line_unittest.cc',
       'tests/ceftests/cookie_unittest.cc',
+      'tests/ceftests/devtools_message_unittest.cc',
       'tests/ceftests/dialog_unittest.cc',
       'tests/ceftests/display_unittest.cc',
       'tests/ceftests/dom_unittest.cc',

include/capi/cef_browser_capi.h

@@ -33,7 +33,7 @@
 // by hand. See the translator.README.txt file in the tools directory for
 // more information.
 //
-// $hash=ba4033eaf40a8ee24408b89b78496bf1381e7e6b$
+// $hash=6cb00a0fa3631a46903abb3a783f315895511db2$
 //
 
 #ifndef CEF_INCLUDE_CAPI_CEF_BROWSER_CAPI_H_
@@ -41,10 +41,12 @@
 #pragma once
 
 #include "include/capi/cef_base_capi.h"
+#include "include/capi/cef_devtools_message_observer_capi.h"
 #include "include/capi/cef_drag_data_capi.h"
 #include "include/capi/cef_frame_capi.h"
 #include "include/capi/cef_image_capi.h"
 #include "include/capi/cef_navigation_entry_capi.h"
+#include "include/capi/cef_registration_capi.h"
 #include "include/capi/cef_request_context_capi.h"
 
 #ifdef __cplusplus
@@ -484,6 +486,71 @@ typedef struct _cef_browser_host_t {
   ///
   int(CEF_CALLBACK* has_dev_tools)(struct _cef_browser_host_t* self);
 
+  ///
+  // Send a function call message over the DevTools protocol. |message| must be
+  // a UTF8-encoded JSON dictionary that contains "id" (int), "function"
+  // (string) and "params" (dictionary, optional) values. See the DevTools
+  // protocol documentation at https://chromedevtools.github.io/devtools-
+  // protocol/ for details of supported functions and the expected "params"
+  // dictionary contents. |message| will be copied if necessary. This function
+  // will return true (1) if called on the UI thread and the message was
+  // successfully submitted for validation, otherwise false (0). Validation will
+  // be applied asynchronously and any messages that fail due to formatting
+  // errors or missing parameters may be discarded without notification. Prefer
+  // ExecuteDevToolsMethod if a more structured approach to message formatting
+  // is desired.
+  //
+  // Every valid function call will result in an asynchronous function result or
+  // error message that references the sent message "id". Event messages are
+  // received while notifications are enabled (for example, between function
+  // calls for "Page.enable" and "Page.disable"). All received messages will be
+  // delivered to the observer(s) registered with AddDevToolsMessageObserver.
+  // See cef_dev_tools_message_observer_t::OnDevToolsMessage documentation for
+  // details of received message contents.
+  //
+  // Usage of the SendDevToolsMessage, ExecuteDevToolsMethod and
+  // AddDevToolsMessageObserver functions does not require an active DevTools
+  // front-end or remote-debugging session. Other active DevTools sessions will
+  // continue to function independently. However, any modification of global
+  // browser state by one session may not be reflected in the UI of other
+  // sessions.
+  //
+  // Communication with the DevTools front-end (when displayed) can be logged
+  // for development purposes by passing the `--devtools-protocol-log-
+  // file=<path>` command-line flag.
+  ///
+  int(CEF_CALLBACK* send_dev_tools_message)(struct _cef_browser_host_t* self,
+                                            const void* message,
+                                            size_t message_size);
+
+  ///
+  // Execute a function call over the DevTools protocol. This is a more
+  // structured version of SendDevToolsMessage. |message_id| is an incremental
+  // number that uniquely identifies the message (pass 0 to have the next number
+  // assigned automatically based on previous values). |function| is the
+  // function name. |params| are the function parameters, which may be NULL. See
+  // the DevTools protocol documentation (linked above) for details of supported
+  // functions and the expected |params| dictionary contents. This function will
+  // return the assigned message ID if called on the UI thread and the message
+  // was successfully submitted for validation, otherwise 0. See the
+  // SendDevToolsMessage documentation for additional usage information.
+  ///
+  int(CEF_CALLBACK* execute_dev_tools_method)(
+      struct _cef_browser_host_t* self,
+      int message_id,
+      const cef_string_t* method,
+      struct _cef_dictionary_value_t* params);
+
+  ///
+  // Add an observer for DevTools protocol messages (function results and
+  // events). The observer will remain registered until the returned
+  // Registration object is destroyed. See the SendDevToolsMessage documentation
+  // for additional usage information.
+  ///
+  struct _cef_registration_t*(CEF_CALLBACK* add_dev_tools_message_observer)(
+      struct _cef_browser_host_t* self,
+      struct _cef_dev_tools_message_observer_t* observer);
+
   ///
   // Retrieve a snapshot of current navigation entries as values sent to the
   // specified visitor. If |current_only| is true (1) only the current

include/capi/cef_devtools_message_observer_capi.h

@@ -0,0 +1,147 @@
+// Copyright (c) 2020 Marshall A. Greenblatt. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//    * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//    * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//    * Neither the name of Google Inc. nor the name Chromium Embedded
+// Framework nor the names of its contributors may be used to endorse
+// or promote products derived from this software without specific prior
+// written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// ---------------------------------------------------------------------------
+//
+// This file was generated by the CEF translator tool and should not edited
+// by hand. See the translator.README.txt file in the tools directory for
+// more information.
+//
+// $hash=86906c2e971fea7e479738f59bbf85d71ce31953$
+//
+
+#ifndef CEF_INCLUDE_CAPI_CEF_DEVTOOLS_MESSAGE_OBSERVER_CAPI_H_
+#define CEF_INCLUDE_CAPI_CEF_DEVTOOLS_MESSAGE_OBSERVER_CAPI_H_
+#pragma once
+
+#include "include/capi/cef_base_capi.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct _cef_browser_t;
+
+///
+// Callback structure for cef_browser_host_t::AddDevToolsMessageObserver. The
+// functions of this structure will be called on the browser process UI thread.
+///
+typedef struct _cef_dev_tools_message_observer_t {
+  ///
+  // Base structure.
+  ///
+  cef_base_ref_counted_t base;
+
+  ///
+  // Method that will be called on receipt of a DevTools protocol message.
+  // |browser| is the originating browser instance. |message| is a UTF8-encoded
+  // JSON dictionary representing either a function result or an event.
+  // |message| is only valid for the scope of this callback and should be copied
+  // if necessary. Return true (1) if the message was handled or false (0) if
+  // the message should be further processed and passed to the
+  // OnDevToolsMethodResult or OnDevToolsEvent functions as appropriate.
+  //
+  // Method result dictionaries include an "id" (int) value that identifies the
+  // orginating function call sent from cef_browser_host_t::SendDevToolsMessage,
+  // and optionally either a "result" (dictionary) or "error" (dictionary)
+  // value. The "error" dictionary will contain "code" (int) and "message"
+  // (string) values. Event dictionaries include a "function" (string) value and
+  // optionally a "params" (dictionary) value. See the DevTools protocol
+  // documentation at https://chromedevtools.github.io/devtools-protocol/ for
+  // details of supported function calls and the expected "result" or "params"
+  // dictionary contents. JSON dictionaries can be parsed using the CefParseJSON
+  // function if desired, however be aware of performance considerations when
+  // parsing large messages (some of which may exceed 1MB in size).
+  ///
+  int(CEF_CALLBACK* on_dev_tools_message)(
+      struct _cef_dev_tools_message_observer_t* self,
+      struct _cef_browser_t* browser,
+      const void* message,
+      size_t message_size);
+
+  ///
+  // Method that will be called after attempted execution of a DevTools protocol
+  // function. |browser| is the originating browser instance. |message_id| is
+  // the "id" value that identifies the originating function call message. If
+  // the function succeeded |success| will be true (1) and |result| will be the
+  // UTF8-encoded JSON "result" dictionary value (which may be NULL). If the
+  // function failed |success| will be false (0) and |result| will be the
+  // UTF8-encoded JSON "error" dictionary value. |result| is only valid for the
+  // scope of this callback and should be copied if necessary. See the
+  // OnDevToolsMessage documentation for additional details on |result|
+  // contents.
+  ///
+  void(CEF_CALLBACK* on_dev_tools_method_result)(
+      struct _cef_dev_tools_message_observer_t* self,
+      struct _cef_browser_t* browser,
+      int message_id,
+      int success,
+      const void* result,
+      size_t result_size);
+
+  ///
+  // Method that will be called on receipt of a DevTools protocol event.
+  // |browser| is the originating browser instance. |function| is the "function"
+  // value. |params| is the UTF8-encoded JSON "params" dictionary value (which
+  // may be NULL). |params| is only valid for the scope of this callback and
+  // should be copied if necessary. See the OnDevToolsMessage documentation for
+  // additional details on |params| contents.
+  ///
+  void(CEF_CALLBACK* on_dev_tools_event)(
+      struct _cef_dev_tools_message_observer_t* self,
+      struct _cef_browser_t* browser,
+      const cef_string_t* method,
+      const void* params,
+      size_t params_size);
+
+  ///
+  // Method that will be called when the DevTools agent has attached. |browser|
+  // is the originating browser instance. This will generally occur in response
+  // to the first message sent while the agent is detached.
+  ///
+  void(CEF_CALLBACK* on_dev_tools_agent_attached)(
+      struct _cef_dev_tools_message_observer_t* self,
+      struct _cef_browser_t* browser);
+
+  ///
+  // Method that will be called when the DevTools agent has detached. |browser|
+  // is the originating browser instance. Any function results that were pending
+  // before the agent became detached will not be delivered, and any active
+  // event subscriptions will be canceled.
+  ///
+  void(CEF_CALLBACK* on_dev_tools_agent_detached)(
+      struct _cef_dev_tools_message_observer_t* self,
+      struct _cef_browser_t* browser);
+} cef_dev_tools_message_observer_t;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // CEF_INCLUDE_CAPI_CEF_DEVTOOLS_MESSAGE_OBSERVER_CAPI_H_

include/capi/cef_parser_capi.h

@@ -33,7 +33,7 @@
 // by hand. See the translator.README.txt file in the tools directory for
 // more information.
 //
-// $hash=3bc4225f43428d8a3a24dcac1830dafac18b0caf$
+// $hash=14cf03e02d8ca3416e65f756470afd8185c7bc78$
 //
 
 #ifndef CEF_INCLUDE_CAPI_CEF_PARSER_CAPI_H_
@@ -140,6 +140,16 @@ CEF_EXPORT struct _cef_value_t* cef_parse_json(
     const cef_string_t* json_string,
     cef_json_parser_options_t options);
 
+///
+// Parses the specified UTF8-encoded |json| buffer of size |json_size| and
+// returns a dictionary or list representation. If JSON parsing fails this
+// function returns NULL.
+///
+CEF_EXPORT struct _cef_value_t* cef_parse_json_buffer(
+    const void* json,
+    size_t json_size,
+    cef_json_parser_options_t options);
+
 ///
 // Parses the specified |json_string| and returns a dictionary or list
 // representation. If JSON parsing fails this function returns NULL and

include/capi/cef_request_handler_capi.h

@@ -33,7 +33,7 @@
 // by hand. See the translator.README.txt file in the tools directory for
 // more information.
 //
-// $hash=a28219cc8c1cb53faacaf236374c3cf2c0c45bef$
+// $hash=0167eb1abe614bd6391d273a8085fa3e53e7c217$
 //
 
 #ifndef CEF_INCLUDE_CAPI_CEF_REQUEST_HANDLER_CAPI_H_
@@ -253,6 +253,14 @@ typedef struct _cef_request_handler_t {
       struct _cef_request_handler_t* self,
       struct _cef_browser_t* browser,
       cef_termination_status_t status);
+
+  ///
+  // Called on the browser process UI thread when the window.document object of
+  // the main frame has been created.
+  ///
+  void(CEF_CALLBACK* on_document_available_in_main_frame)(
+      struct _cef_request_handler_t* self,
+      struct _cef_browser_t* browser);
 } cef_request_handler_t;
 
 #ifdef __cplusplus

include/cef_api_hash.h

@@ -42,13 +42,13 @@
 // way that may cause binary incompatibility with other builds. The universal
 // hash value will change if any platform is affected whereas the platform hash
 // values will change only if that particular platform is affected.
-#define CEF_API_HASH_UNIVERSAL "a48c939496261acf27f45293484f2c9e4065ca6f"
+#define CEF_API_HASH_UNIVERSAL "eb44c98407c9286a64b8d872f49c772b3fa3eb63"
 #if defined(OS_WIN)
-#define CEF_API_HASH_PLATFORM "7ab8365e6f76e376342247954be2f90f69014776"
+#define CEF_API_HASH_PLATFORM "365b52117c7adf0a8bb6d96638954eb313168ff7"
 #elif defined(OS_MACOSX)
-#define CEF_API_HASH_PLATFORM "01cc20ae8dbd5ce63ff50cac215855c4c58059f4"
+#define CEF_API_HASH_PLATFORM "1d1bca66ca61d742f507c08d4efda9884c94baff"
 #elif defined(OS_LINUX)
-#define CEF_API_HASH_PLATFORM "112ef821732253dfda925d4a1a6d490396bac6d2"
+#define CEF_API_HASH_PLATFORM "a87fd1ea68d4e79c838538fa78d79f8dd05acab2"
 #endif
 
 #ifdef __cplusplus

include/cef_browser.h

@@ -40,10 +40,12 @@
 
 #include <vector>
 #include "include/cef_base.h"
+#include "include/cef_devtools_message_observer.h"
 #include "include/cef_drag_data.h"
 #include "include/cef_frame.h"
 #include "include/cef_image.h"
 #include "include/cef_navigation_entry.h"
+#include "include/cef_registration.h"
 #include "include/cef_request_context.h"
 
 class CefBrowserHost;
@@ -517,6 +519,69 @@ class CefBrowserHost : public virtual CefBaseRefCounted {
   /*--cef()--*/
   virtual bool HasDevTools() = 0;
 
+  ///
+  // Send a method call message over the DevTools protocol. |message| must be a
+  // UTF8-encoded JSON dictionary that contains "id" (int), "method" (string)
+  // and "params" (dictionary, optional) values. See the DevTools protocol
+  // documentation at https://chromedevtools.github.io/devtools-protocol/ for
+  // details of supported methods and the expected "params" dictionary contents.
+  // |message| will be copied if necessary. This method will return true if
+  // called on the UI thread and the message was successfully submitted for
+  // validation, otherwise false. Validation will be applied asynchronously and
+  // any messages that fail due to formatting errors or missing parameters may
+  // be discarded without notification. Prefer ExecuteDevToolsMethod if a more
+  // structured approach to message formatting is desired.
+  //
+  // Every valid method call will result in an asynchronous method result or
+  // error message that references the sent message "id". Event messages are
+  // received while notifications are enabled (for example, between method calls
+  // for "Page.enable" and "Page.disable"). All received messages will be
+  // delivered to the observer(s) registered with AddDevToolsMessageObserver.
+  // See CefDevToolsMessageObserver::OnDevToolsMessage documentation for details
+  // of received message contents.
+  //
+  // Usage of the SendDevToolsMessage, ExecuteDevToolsMethod and
+  // AddDevToolsMessageObserver methods does not require an active DevTools
+  // front-end or remote-debugging session. Other active DevTools sessions will
+  // continue to function independently. However, any modification of global
+  // browser state by one session may not be reflected in the UI of other
+  // sessions.
+  //
+  // Communication with the DevTools front-end (when displayed) can be logged
+  // for development purposes by passing the
+  // `--devtools-protocol-log-file=<path>` command-line flag.
+  ///
+  /*--cef()--*/
+  virtual bool SendDevToolsMessage(const void* message,
+                                   size_t message_size) = 0;
+
+  ///
+  // Execute a method call over the DevTools protocol. This is a more structured
+  // version of SendDevToolsMessage. |message_id| is an incremental number that
+  // uniquely identifies the message (pass 0 to have the next number assigned
+  // automatically based on previous values). |method| is the method name.
+  // |params| are the method parameters, which may be empty. See the DevTools
+  // protocol documentation (linked above) for details of supported methods and
+  // the expected |params| dictionary contents. This method will return the
+  // assigned message ID if called on the UI thread and the message was
+  // successfully submitted for validation, otherwise 0. See the
+  // SendDevToolsMessage documentation for additional usage information.
+  ///
+  /*--cef(optional_param=params)--*/
+  virtual int ExecuteDevToolsMethod(int message_id,
+                                    const CefString& method,
+                                    CefRefPtr<CefDictionaryValue> params) = 0;
+
+  ///
+  // Add an observer for DevTools protocol messages (method results and events).
+  // The observer will remain registered until the returned Registration object
+  // is destroyed. See the SendDevToolsMessage documentation for additional
+  // usage information.
+  ///
+  /*--cef()--*/
+  virtual CefRefPtr<CefRegistration> AddDevToolsMessageObserver(
+      CefRefPtr<CefDevToolsMessageObserver> observer) = 0;
+
   ///
   // Retrieve a snapshot of current navigation entries as values sent to the
   // specified visitor. If |current_only| is true only the current navigation

include/cef_devtools_message_observer.h

@@ -0,0 +1,130 @@
+// Copyright (c) 2020 Marshall A. Greenblatt. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//    * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//    * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//    * Neither the name of Google Inc. nor the name Chromium Embedded
+// Framework nor the names of its contributors may be used to endorse
+// or promote products derived from this software without specific prior
+// written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// ---------------------------------------------------------------------------
+//
+// The contents of this file must follow a specific format in order to
+// support the CEF translator tool. See the translator.README.txt file in the
+// tools directory for more information.
+//
+
+#ifndef CEF_INCLUDE_CEF_DEVTOOLS_MESSAGE_OBSERVER_H_
+#define CEF_INCLUDE_CEF_DEVTOOLS_MESSAGE_OBSERVER_H_
+#pragma once
+
+#include "include/cef_base.h"
+
+class CefBrowser;
+
+///
+// Callback interface for CefBrowserHost::AddDevToolsMessageObserver. The
+// methods of this class will be called on the browser process UI thread.
+///
+/*--cef(source=client)--*/
+class CefDevToolsMessageObserver : public virtual CefBaseRefCounted {
+ public:
+  ///
+  // Method that will be called on receipt of a DevTools protocol message.
+  // |browser| is the originating browser instance. |message| is a UTF8-encoded
+  // JSON dictionary representing either a method result or an event. |message|
+  // is only valid for the scope of this callback and should be copied if
+  // necessary. Return true if the message was handled or false if the message
+  // should be further processed and passed to the OnDevToolsMethodResult or
+  // OnDevToolsEvent methods as appropriate.
+  //
+  // Method result dictionaries include an "id" (int) value that identifies the
+  // orginating method call sent from CefBrowserHost::SendDevToolsMessage, and
+  // optionally either a "result" (dictionary) or "error" (dictionary) value.
+  // The "error" dictionary will contain "code" (int) and "message" (string)
+  // values. Event dictionaries include a "method" (string) value and optionally
+  // a "params" (dictionary) value. See the DevTools protocol documentation at
+  // https://chromedevtools.github.io/devtools-protocol/ for details of
+  // supported method calls and the expected "result" or "params" dictionary
+  // contents. JSON dictionaries can be parsed using the CefParseJSON function
+  // if desired, however be aware of performance considerations when parsing
+  // large messages (some of which may exceed 1MB in size).
+  ///
+  /*--cef()--*/
+  virtual bool OnDevToolsMessage(CefRefPtr<CefBrowser> browser,
+                                 const void* message,
+                                 size_t message_size) {
+    return false;
+  }
+
+  ///
+  // Method that will be called after attempted execution of a DevTools protocol
+  // method. |browser| is the originating browser instance. |message_id| is the
+  // "id" value that identifies the originating method call message. If the
+  // method succeeded |success| will be true and |result| will be the
+  // UTF8-encoded JSON "result" dictionary value (which may be empty). If the
+  // method failed |success| will be false and |result| will be the UTF8-encoded
+  // JSON "error" dictionary value. |result| is only valid for the scope of this
+  // callback and should be copied if necessary. See the OnDevToolsMessage
+  // documentation for additional details on |result| contents.
+  ///
+  /*--cef(optional_param=result)--*/
+  virtual void OnDevToolsMethodResult(CefRefPtr<CefBrowser> browser,
+                                      int message_id,
+                                      bool success,
+                                      const void* result,
+                                      size_t result_size) {}
+
+  ///
+  // Method that will be called on receipt of a DevTools protocol event.
+  // |browser| is the originating browser instance. |method| is the "method"
+  // value. |params| is the UTF8-encoded JSON "params" dictionary value (which
+  // may be empty). |params| is only valid for the scope of this callback and
+  // should be copied if necessary. See the OnDevToolsMessage documentation for
+  // additional details on |params| contents.
+  ///
+  /*--cef(optional_param=params)--*/
+  virtual void OnDevToolsEvent(CefRefPtr<CefBrowser> browser,
+                               const CefString& method,
+                               const void* params,
+                               size_t params_size) {}
+
+  ///
+  // Method that will be called when the DevTools agent has attached. |browser|
+  // is the originating browser instance. This will generally occur in response
+  // to the first message sent while the agent is detached.
+  ///
+  /*--cef()--*/
+  virtual void OnDevToolsAgentAttached(CefRefPtr<CefBrowser> browser) {}
+
+  ///
+  // Method that will be called when the DevTools agent has detached. |browser|
+  // is the originating browser instance. Any method results that were pending
+  // before the agent became detached will not be delivered, and any active
+  // event subscriptions will be canceled.
+  ///
+  /*--cef()--*/
+  virtual void OnDevToolsAgentDetached(CefRefPtr<CefBrowser> browser) {}
+};
+
+#endif  // CEF_INCLUDE_CEF_DEVTOOLS_MESSAGE_OBSERVER_H_

include/cef_parser.h

@@ -133,6 +133,16 @@ CefString CefURIDecode(const CefString& text,
 CefRefPtr<CefValue> CefParseJSON(const CefString& json_string,
                                  cef_json_parser_options_t options);
 
+///
+// Parses the specified UTF8-encoded |json| buffer of size |json_size| and
+// returns a dictionary or list representation. If JSON parsing fails this
+// method returns NULL.
+///
+/*--cef(capi_name=cef_parse_json_buffer)--*/
+CefRefPtr<CefValue> CefParseJSON(const void* json,
+                                 size_t json_size,
+                                 cef_json_parser_options_t options);
+
 ///
 // Parses the specified |json_string| and returns a dictionary or list
 // representation. If JSON parsing fails this method returns NULL and populates

include/cef_request_handler.h

@@ -252,6 +252,13 @@ class CefRequestHandler : public virtual CefBaseRefCounted {
   /*--cef()--*/
   virtual void OnRenderProcessTerminated(CefRefPtr<CefBrowser> browser,
                                          TerminationStatus status) {}
+
+  ///
+  // Called on the browser process UI thread when the window.document object of
+  // the main frame has been created.
+  ///
+  /*--cef()--*/
+  virtual void OnDocumentAvailableInMainFrame(CefRefPtr<CefBrowser> browser) {}
 };
 
 #endif  // CEF_INCLUDE_CEF_REQUEST_HANDLER_H_

libcef/browser/browser_host_impl.cc

@@ -16,8 +16,7 @@
 #include "libcef/browser/browser_util.h"
 #include "libcef/browser/content_browser_client.h"
 #include "libcef/browser/context.h"
-#include "libcef/browser/devtools/devtools_frontend.h"
+#include "libcef/browser/devtools/devtools_manager.h"
-#include "libcef/browser/devtools/devtools_manager_delegate.h"
 #include "libcef/browser/extensions/browser_extensions_util.h"
 #include "libcef/browser/extensions/extension_background_host.h"
 #include "libcef/browser/extensions/extension_system.h"
@@ -594,26 +593,6 @@ CefRefPtr<CefBrowserHostImpl> CefBrowserHostImpl::GetBrowserForFrameRoute(
 // CefBrowserHostImpl methods.
 // -----------------------------------------------------------------------------
 
-// WebContentsObserver that will be notified when the frontend WebContents is
-// destroyed so that the inspected browser can clear its DevTools references.
-class CefBrowserHostImpl::DevToolsWebContentsObserver
-    : public content::WebContentsObserver {
- public:
-  DevToolsWebContentsObserver(CefBrowserHostImpl* browser,
-                              content::WebContents* frontend_web_contents)
-      : WebContentsObserver(frontend_web_contents), browser_(browser) {}
-
-  // WebContentsObserver methods:
-  void WebContentsDestroyed() override {
-    browser_->OnDevToolsWebContentsDestroyed();
-  }
-
- private:
-  CefBrowserHostImpl* browser_;
-
-  DISALLOW_COPY_AND_ASSIGN(DevToolsWebContentsObserver);
-};
-
 CefBrowserHostImpl::~CefBrowserHostImpl() {}
 
 CefRefPtr<CefBrowser> CefBrowserHostImpl::GetBrowser() {
@@ -906,39 +885,29 @@ void CefBrowserHostImpl::ShowDevTools(const CefWindowInfo& windowInfo,
                                       CefRefPtr<CefClient> client,
                                       const CefBrowserSettings& settings,
                                       const CefPoint& inspect_element_at) {
-  if (CEF_CURRENTLY_ON_UIT()) {
+  if (!CEF_CURRENTLY_ON_UIT()) {
-    if (!web_contents())
-      return;
-
-    if (devtools_frontend_) {
-      if (!inspect_element_at.IsEmpty()) {
-        devtools_frontend_->InspectElementAt(inspect_element_at.x,
-                                             inspect_element_at.y);
-      }
-      devtools_frontend_->Focus();
-      return;
-    }
-
-    devtools_frontend_ = CefDevToolsFrontend::Show(
-        this, windowInfo, client, settings, inspect_element_at);
-    devtools_observer_.reset(new DevToolsWebContentsObserver(
-        this, devtools_frontend_->frontend_browser()->web_contents()));
-  } else {
     ShowDevToolsHelper* helper = new ShowDevToolsHelper(
         this, windowInfo, client, settings, inspect_element_at);
     CEF_POST_TASK(CEF_UIT, base::BindOnce(ShowDevToolsWithHelper, helper));
+    return;
   }
+
+  if (!EnsureDevToolsManager())
+    return;
+  devtools_manager_->ShowDevTools(windowInfo, client, settings,
+                                  inspect_element_at);
 }
 
 void CefBrowserHostImpl::CloseDevTools() {
-  if (CEF_CURRENTLY_ON_UIT()) {
+  if (!CEF_CURRENTLY_ON_UIT()) {
-    if (!devtools_frontend_)
-      return;
-    devtools_frontend_->Close();
-  } else {
     CEF_POST_TASK(CEF_UIT,
                   base::BindOnce(&CefBrowserHostImpl::CloseDevTools, this));
+    return;
   }
+
+  if (!devtools_manager_)
+    return;
+  devtools_manager_->CloseDevTools();
 }
 
 bool CefBrowserHostImpl::HasDevTools() {
@@ -947,7 +916,84 @@ bool CefBrowserHostImpl::HasDevTools() {
     return false;
   }
 
-  return (devtools_frontend_ != nullptr);
+  if (!devtools_manager_)
+    return false;
+  return devtools_manager_->HasDevTools();
+}
+
+bool CefBrowserHostImpl::SendDevToolsMessage(const void* message,
+                                             size_t message_size) {
+  if (!message || message_size == 0)
+    return false;
+
+  if (!CEF_CURRENTLY_ON_UIT()) {
+    std::string message_str(static_cast<const char*>(message), message_size);
+    CEF_POST_TASK(
+        CEF_UIT,
+        base::BindOnce(
+            [](CefRefPtr<CefBrowserHostImpl> self, std::string message_str) {
+              self->SendDevToolsMessage(message_str.data(), message_str.size());
+            },
+            CefRefPtr<CefBrowserHostImpl>(this), std::move(message_str)));
+    return false;
+  }
+
+  if (!EnsureDevToolsManager())
+    return false;
+  return devtools_manager_->SendDevToolsMessage(message, message_size);
+}
+
+int CefBrowserHostImpl::ExecuteDevToolsMethod(
+    int message_id,
+    const CefString& method,
+    CefRefPtr<CefDictionaryValue> params) {
+  if (!CEF_CURRENTLY_ON_UIT()) {
+    CEF_POST_TASK(
+        CEF_UIT, base::BindOnce(base::IgnoreResult(
+                                    &CefBrowserHostImpl::ExecuteDevToolsMethod),
+                                this, message_id, method, params));
+    return 0;
+  }
+
+  if (!EnsureDevToolsManager())
+    return 0;
+  return devtools_manager_->ExecuteDevToolsMethod(message_id, method, params);
+}
+
+CefRefPtr<CefRegistration> CefBrowserHostImpl::AddDevToolsMessageObserver(
+    CefRefPtr<CefDevToolsMessageObserver> observer) {
+  if (!observer)
+    return nullptr;
+  auto registration = CefDevToolsManager::CreateRegistration(observer);
+  InitializeDevToolsRegistrationOnUIThread(registration);
+  return registration.get();
+}
+
+bool CefBrowserHostImpl::EnsureDevToolsManager() {
+  CEF_REQUIRE_UIT();
+  if (!web_contents())
+    return false;
+
+  if (!devtools_manager_) {
+    devtools_manager_.reset(new CefDevToolsManager(this));
+  }
+  return true;
+}
+
+void CefBrowserHostImpl::InitializeDevToolsRegistrationOnUIThread(
+    CefRefPtr<CefRegistration> registration) {
+  if (!CEF_CURRENTLY_ON_UIT()) {
+    CEF_POST_TASK(
+        CEF_UIT,
+        base::BindOnce(
+            &CefBrowserHostImpl::InitializeDevToolsRegistrationOnUIThread, this,
+            registration));
+    return;
+  }
+
+  if (!EnsureDevToolsManager())
+    return;
+  devtools_manager_->InitializeRegistrationOnUIThread(registration);
 }
 
 void CefBrowserHostImpl::GetNavigationEntries(
@@ -1611,6 +1657,8 @@ void CefBrowserHostImpl::DestroyBrowser() {
   recently_audible_timer_.Stop();
   audio_capturer_.reset(nullptr);
 
+  devtools_manager_.reset(nullptr);
+
   // Delete the platform delegate.
   platform_delegate_.reset(nullptr);
 
@@ -2704,16 +2752,24 @@ void CefBrowserHostImpl::DidStopLoading() {
 }
 
 void CefBrowserHostImpl::DocumentAvailableInMainFrame() {
-  base::AutoLock lock_scope(state_lock_);
+  {
-  has_document_ = true;
+    base::AutoLock lock_scope(state_lock_);
+    has_document_ = true;
+  }
+
+  if (client_) {
+    CefRefPtr<CefRequestHandler> handler = client_->GetRequestHandler();
+    if (handler)
+      handler->OnDocumentAvailableInMainFrame(this);
+  }
 }
 
 void CefBrowserHostImpl::DidFailLoad(
     content::RenderFrameHost* render_frame_host,
     const GURL& validated_url,
     int error_code) {
-  // The navigation failed after commit. OnLoadStart was called so we also call
+  // The navigation failed after commit. OnLoadStart was called so we also
-  // OnLoadEnd.
+  // call OnLoadEnd.
   auto frame = browser_info_->GetFrameForHost(render_frame_host);
   frame->RefreshAttributes();
   OnLoadError(frame, validated_url, error_code);
@@ -2949,18 +3005,6 @@ CefBrowserHostImpl::CefBrowserHostImpl(
       platform_delegate_(std::move(platform_delegate)),
       is_windowless_(platform_delegate_->IsWindowless()),
       is_views_hosted_(platform_delegate_->IsViewsHosted()),
-      host_window_handle_(kNullWindowHandle),
-      is_loading_(false),
-      can_go_back_(false),
-      can_go_forward_(false),
-      has_document_(false),
-      is_fullscreen_(false),
-      destruction_state_(DESTRUCTION_STATE_NONE),
-      window_destroyed_(false),
-      is_in_onsetfocus_(false),
-      focus_on_editable_field_(false),
-      mouse_cursor_change_disabled_(false),
-      devtools_frontend_(nullptr),
       extension_(extension) {
   if (opener.get() && !platform_delegate_->IsViewsHosted()) {
     // GetOpenerWindowHandle() only returns a value for non-views-hosted
@@ -3171,11 +3215,6 @@ void CefBrowserHostImpl::OnTitleChange(const base::string16& title) {
   }
 }
 
-void CefBrowserHostImpl::OnDevToolsWebContentsDestroyed() {
-  devtools_observer_.reset();
-  devtools_frontend_ = nullptr;
-}
-
 void CefBrowserHostImpl::EnsureFileDialogManager() {
   CEF_REQUIRE_UIT();
   if (!file_dialog_manager_.get() && platform_delegate_) {

libcef/browser/browser_host_impl.h

@@ -51,7 +51,7 @@ class Widget;
 class CefAudioCapturer;
 class CefBrowserInfo;
 class CefBrowserPlatformDelegate;
-class CefDevToolsFrontend;
+class CefDevToolsManager;
 class SiteInstance;
 
 // Implementation of CefBrowser.
@@ -192,6 +192,12 @@ class CefBrowserHostImpl : public CefBrowserHost,
                     const CefPoint& inspect_element_at) override;
   void CloseDevTools() override;
   bool HasDevTools() override;
+  bool SendDevToolsMessage(const void* message, size_t message_size) override;
+  int ExecuteDevToolsMethod(int message_id,
+                            const CefString& method,
+                            CefRefPtr<CefDictionaryValue> params) override;
+  CefRefPtr<CefRegistration> AddDevToolsMessageObserver(
+      CefRefPtr<CefDevToolsMessageObserver> observer) override;
   void GetNavigationEntries(CefRefPtr<CefNavigationEntryVisitor> visitor,
                             bool current_only) override;
   void SetMouseCursorChangeDisabled(bool disabled) override;
@@ -523,8 +529,6 @@ class CefBrowserHostImpl : public CefBrowserHost,
   std::unique_ptr<NavigationLock> CreateNavigationLock();
 
  private:
-  class DevToolsWebContentsObserver;
-
   static CefRefPtr<CefBrowserHostImpl> CreateInternal(
       const CefBrowserSettings& settings,
       CefRefPtr<CefClient> client,
@@ -581,8 +585,6 @@ class CefBrowserHostImpl : public CefBrowserHost,
   void OnFullscreenModeChange(bool fullscreen);
   void OnTitleChange(const base::string16& title);
 
-  void OnDevToolsWebContentsDestroyed();
-
   // Create the CefFileDialogManager if it doesn't already exist.
   void EnsureFileDialogManager();
 
@@ -591,6 +593,10 @@ class CefBrowserHostImpl : public CefBrowserHost,
   void StartAudioCapturer();
   void OnRecentlyAudibleTimerFired();
 
+  bool EnsureDevToolsManager();
+  void InitializeDevToolsRegistrationOnUIThread(
+      CefRefPtr<CefRegistration> registration);
+
   CefBrowserSettings settings_;
   CefRefPtr<CefClient> client_;
   scoped_refptr<CefBrowserInfo> browser_info_;
@@ -599,7 +605,7 @@ class CefBrowserHostImpl : public CefBrowserHost,
   std::unique_ptr<CefBrowserPlatformDelegate> platform_delegate_;
   const bool is_windowless_;
   const bool is_views_hosted_;
-  CefWindowHandle host_window_handle_;
+  CefWindowHandle host_window_handle_ = kNullWindowHandle;
 
   // Non-nullptr if this object owns the WebContents. Will be nullptr for popup
   // browsers between the calls to WebContentsCreated() and AddNewContents(),
@@ -609,18 +615,18 @@ class CefBrowserHostImpl : public CefBrowserHost,
 
   // Volatile state information. All access must be protected by the state lock.
   base::Lock state_lock_;
-  bool is_loading_;
+  bool is_loading_ = false;
-  bool can_go_back_;
+  bool can_go_back_ = false;
-  bool can_go_forward_;
+  bool can_go_forward_ = false;
-  bool has_document_;
+  bool has_document_ = false;
-  bool is_fullscreen_;
+  bool is_fullscreen_ = false;
 
   // The currently focused frame, or nullptr if the main frame is focused.
   CefRefPtr<CefFrameHostImpl> focused_frame_;
 
   // Represents the current browser destruction state. Only accessed on the UI
   // thread.
-  DestructionState destruction_state_;
+  DestructionState destruction_state_ = DESTRUCTION_STATE_NONE;
 
   // Navigation will not occur while |navigation_lock_count_| > 0.
   // |pending_navigation_action_| will be executed when the lock is released.
@@ -630,18 +636,18 @@ class CefBrowserHostImpl : public CefBrowserHost,
 
   // True if the OS window hosting the browser has been destroyed. Only accessed
   // on the UI thread.
-  bool window_destroyed_;
+  bool window_destroyed_ = false;
 
   // True if currently in the OnSetFocus callback. Only accessed on the UI
   // thread.
-  bool is_in_onsetfocus_;
+  bool is_in_onsetfocus_ = false;
 
   // True if the focus is currently on an editable field on the page. Only
   // accessed on the UI thread.
-  bool focus_on_editable_field_;
+  bool focus_on_editable_field_ = false;
 
   // True if mouse cursor change is disabled.
-  bool mouse_cursor_change_disabled_;
+  bool mouse_cursor_change_disabled_ = false;
 
   // Used for managing notification subscriptions.
   std::unique_ptr<content::NotificationRegistrar> registrar_;
@@ -655,12 +661,8 @@ class CefBrowserHostImpl : public CefBrowserHost,
   // Used for creating and managing context menus.
   std::unique_ptr<CefMenuManager> menu_manager_;
 
-  // Track the lifespan of the frontend WebContents associated with this
+  // Used for creating and managing DevTools instances.
-  // browser.
+  std::unique_ptr<CefDevToolsManager> devtools_manager_;
-  std::unique_ptr<DevToolsWebContentsObserver> devtools_observer_;
-  // CefDevToolsFrontend will delete itself when the frontend WebContents is
-  // destroyed.
-  CefDevToolsFrontend* devtools_frontend_;
 
   // Observers that want to be notified of changes to this object.
   base::ObserverList<Observer>::Unchecked observers_;

libcef/browser/devtools/devtools_controller.cc

@@ -0,0 +1,137 @@
+// Copyright (c) 2020 The Chromium Embedded Framework Authors. All rights
+// reserved. Use of this source code is governed by a BSD-style license that
+// can be found in the LICENSE file.
+
+#include "libcef/browser/devtools/devtools_controller.h"
+
+#include "libcef/browser/devtools/devtools_util.h"
+#include "libcef/browser/thread_util.h"
+
+#include "base/json/json_reader.h"
+#include "base/json/json_writer.h"
+#include "content/public/browser/devtools_agent_host.h"
+
+CefDevToolsController::CefDevToolsController(
+    content::WebContents* inspected_contents)
+    : inspected_contents_(inspected_contents), weak_ptr_factory_(this) {
+  DCHECK(inspected_contents_);
+}
+
+CefDevToolsController::~CefDevToolsController() {
+  if (agent_host_) {
+    agent_host_->DetachClient(this);
+    AgentHostClosed(agent_host_.get());
+  }
+
+  for (auto& observer : observers_) {
+    observer.OnDevToolsControllerDestroyed();
+  }
+}
+
+bool CefDevToolsController::SendDevToolsMessage(
+    const base::StringPiece& message) {
+  CEF_REQUIRE_UIT();
+  if (!EnsureAgentHost())
+    return false;
+
+  agent_host_->DispatchProtocolMessage(
+      this, base::as_bytes(base::make_span(message)));
+  return true;
+}
+
+int CefDevToolsController::ExecuteDevToolsMethod(
+    int suggested_message_id,
+    const std::string& method,
+    const base::DictionaryValue* params) {
+  CEF_REQUIRE_UIT();
+  if (!EnsureAgentHost())
+    return 0;
+
+  // Message IDs must always be increasing and unique.
+  int message_id = suggested_message_id;
+  if (message_id < next_message_id_)
+    message_id = next_message_id_++;
+  else
+    next_message_id_ = message_id + 1;
+
+  base::DictionaryValue message;
+  message.SetIntKey("id", message_id);
+  message.SetStringKey("method", method);
+  if (params)
+    message.SetKey("params", params->Clone());
+
+  std::string protocol_message;
+  if (!base::JSONWriter::Write(message, &protocol_message))
+    return 0;
+
+  agent_host_->DispatchProtocolMessage(
+      this, base::as_bytes(base::make_span(protocol_message)));
+  return message_id;
+}
+
+void CefDevToolsController::AgentHostClosed(
+    content::DevToolsAgentHost* agent_host) {
+  DCHECK(agent_host == agent_host_.get());
+  agent_host_ = nullptr;
+  for (auto& observer : observers_) {
+    observer.OnDevToolsAgentDetached();
+  }
+}
+
+void CefDevToolsController::AddObserver(Observer* observer) {
+  CEF_REQUIRE_UIT();
+  observers_.AddObserver(observer);
+}
+
+void CefDevToolsController::RemoveObserver(Observer* observer) {
+  CEF_REQUIRE_UIT();
+  observers_.RemoveObserver(observer);
+}
+
+void CefDevToolsController::DispatchProtocolMessage(
+    content::DevToolsAgentHost* agent_host,
+    base::span<const uint8_t> message) {
+  if (!observers_.might_have_observers())
+    return;
+
+  base::StringPiece str_message(reinterpret_cast<const char*>(message.data()),
+                                message.size());
+  if (!devtools_util::ProtocolParser::IsValidMessage(str_message)) {
+    LOG(WARNING) << "Invalid message: " << str_message.substr(0, 100);
+    return;
+  }
+
+  devtools_util::ProtocolParser parser;
+
+  for (auto& observer : observers_) {
+    if (observer.OnDevToolsMessage(str_message)) {
+      continue;
+    }
+
+    // Only perform parsing a single time.
+    if (parser.Initialize(str_message) && parser.IsFailure()) {
+      LOG(WARNING) << "Failed to parse message: " << str_message.substr(0, 100);
+    }
+
+    if (parser.IsEvent()) {
+      observer.OnDevToolsEvent(parser.method_, parser.params_);
+    } else if (parser.IsResult()) {
+      observer.OnDevToolsMethodResult(parser.message_id_, parser.success_,
+                                      parser.params_);
+    }
+  }
+}
+
+bool CefDevToolsController::EnsureAgentHost() {
+  if (!agent_host_) {
+    agent_host_ =
+        content::DevToolsAgentHost::GetOrCreateFor(inspected_contents_);
+    if (agent_host_) {
+      agent_host_->AttachClient(this);
+      for (auto& observer : observers_) {
+        observer.OnDevToolsAgentAttached();
+      }
+    }
+  }
+  return !!agent_host_;
+}

libcef/browser/devtools/devtools_controller.h

@@ -0,0 +1,79 @@
+// Copyright (c) 2020 The Chromium Embedded Framework Authors. All rights
+// reserved. Use of this source code is governed by a BSD-style license that
+// can be found in the LICENSE file.
+
+#ifndef CEF_LIBCEF_BROWSER_DEVTOOLS_DEVTOOLS_CONTROLLER_H_
+#define CEF_LIBCEF_BROWSER_DEVTOOLS_DEVTOOLS_CONTROLLER_H_
+
+#include <memory>
+
+#include "content/public/browser/devtools_agent_host_client.h"
+
+#include "base/containers/span.h"
+#include "base/memory/scoped_refptr.h"
+#include "base/memory/weak_ptr.h"
+#include "base/observer_list.h"
+#include "base/values.h"
+
+namespace content {
+class WebContents;
+}
+
+class CefDevToolsController : public content::DevToolsAgentHostClient {
+ public:
+  class Observer : public base::CheckedObserver {
+   public:
+    // See CefDevToolsMessageObserver documentation.
+    virtual bool OnDevToolsMessage(const base::StringPiece& message) = 0;
+    virtual void OnDevToolsMethodResult(int message_id,
+                                        bool success,
+                                        const base::StringPiece& result) = 0;
+    virtual void OnDevToolsEvent(const base::StringPiece& method,
+                                 const base::StringPiece& params) = 0;
+    virtual void OnDevToolsAgentAttached() = 0;
+    virtual void OnDevToolsAgentDetached() = 0;
+
+    virtual void OnDevToolsControllerDestroyed() = 0;
+
+   protected:
+    ~Observer() override {}
+  };
+
+  // |inspected_contents| will outlive this object.
+  explicit CefDevToolsController(content::WebContents* inspected_contents);
+  ~CefDevToolsController() override;
+
+  // See CefBrowserHost methods of the same name for documentation.
+  bool SendDevToolsMessage(const base::StringPiece& message);
+  int ExecuteDevToolsMethod(int message_id,
+                            const std::string& method,
+                            const base::DictionaryValue* params);
+
+  // |observer| must outlive this object or be removed.
+  void AddObserver(Observer* observer);
+  void RemoveObserver(Observer* observer);
+
+  base::WeakPtr<CefDevToolsController> GetWeakPtr() {
+    return weak_ptr_factory_.GetWeakPtr();
+  }
+
+ private:
+  // content::DevToolsAgentHostClient implementation:
+  void AgentHostClosed(content::DevToolsAgentHost* agent_host) override;
+  void DispatchProtocolMessage(content::DevToolsAgentHost* agent_host,
+                               base::span<const uint8_t> message) override;
+
+  bool EnsureAgentHost();
+
+  content::WebContents* const inspected_contents_;
+  scoped_refptr<content::DevToolsAgentHost> agent_host_;
+  int next_message_id_ = 1;
+
+  base::ObserverList<Observer> observers_;
+
+  base::WeakPtrFactory<CefDevToolsController> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(CefDevToolsController);
+};
+
+#endif  // CEF_LIBCEF_BROWSER_DEVTOOLS_DEVTOOLS_CONTROLLER_H_

libcef/browser/devtools/devtools_frontend.cc

@@ -6,13 +6,18 @@
 
 #include <stddef.h>
 
+#include <iomanip>
 #include <utility>
 
 #include "libcef/browser/browser_context.h"
+#include "libcef/browser/content_browser_client.h"
 #include "libcef/browser/devtools/devtools_manager_delegate.h"
 #include "libcef/browser/net/devtools_scheme_handler.h"
+#include "libcef/common/cef_switches.h"
 
 #include "base/base64.h"
+#include "base/command_line.h"
+#include "base/files/file_util.h"
 #include "base/guid.h"
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
@@ -48,6 +53,13 @@
 #include "services/network/public/cpp/simple_url_loader.h"
 #include "services/network/public/cpp/simple_url_loader_stream_consumer.h"
 #include "services/network/public/mojom/url_response_head.mojom.h"
+#include "storage/browser/file_system/native_file_util.h"
+
+#if defined(OS_WIN)
+#include <windows.h>
+#elif defined(OS_POSIX)
+#include <time.h>
+#endif
 
 namespace {
 
@@ -86,6 +98,71 @@ std::unique_ptr<base::DictionaryValue> BuildObjectForResponse(
   return response;
 }
 
+const int kMaxLogLineLength = 1024;
+
+void WriteTimestamp(std::stringstream& stream) {
+#if defined(OS_WIN)
+  SYSTEMTIME local_time;
+  GetLocalTime(&local_time);
+  stream << std::setfill('0') << std::setw(2) << local_time.wMonth
+         << std::setw(2) << local_time.wDay << '/' << std::setw(2)
+         << local_time.wHour << std::setw(2) << local_time.wMinute
+         << std::setw(2) << local_time.wSecond << '.' << std::setw(3)
+         << local_time.wMilliseconds;
+#elif defined(OS_POSIX)
+  timeval tv;
+  gettimeofday(&tv, nullptr);
+  time_t t = tv.tv_sec;
+  struct tm local_time;
+  localtime_r(&t, &local_time);
+  struct tm* tm_time = &local_time;
+  stream << std::setfill('0') << std::setw(2) << 1 + tm_time->tm_mon
+         << std::setw(2) << tm_time->tm_mday << '/' << std::setw(2)
+         << tm_time->tm_hour << std::setw(2) << tm_time->tm_min << std::setw(2)
+         << tm_time->tm_sec << '.' << std::setw(6) << tv.tv_usec;
+#else
+#error Unsupported platform
+#endif
+}
+
+void LogProtocolMessage(const base::FilePath& log_file,
+                        ProtocolMessageType type,
+                        std::string to_log) {
+  // Track if logging has failed, in which case we don't keep trying.
+  static bool log_error = false;
+  if (log_error)
+    return;
+
+  if (storage::NativeFileUtil::EnsureFileExists(log_file, nullptr) !=
+      base::File::FILE_OK) {
+    LOG(ERROR) << "Failed to create file " << log_file.value();
+    log_error = true;
+    return;
+  }
+
+  std::string type_label;
+  switch (type) {
+    case ProtocolMessageType::METHOD:
+      type_label = "METHOD";
+      break;
+    case ProtocolMessageType::RESULT:
+      type_label = "RESULT";
+      break;
+    case ProtocolMessageType::EVENT:
+      type_label = "EVENT";
+      break;
+  }
+
+  std::stringstream stream;
+  WriteTimestamp(stream);
+  stream << ": " << type_label << ": " << to_log << "\n";
+  const std::string& str = stream.str();
+  if (!base::AppendToFile(log_file, str.c_str(), str.size())) {
+    LOG(ERROR) << "Failed to write file " << log_file.value();
+    log_error = true;
+  }
+}
+
 }  // namespace
 
 class CefDevToolsFrontend::NetworkResourceLoader
@@ -156,11 +233,12 @@ const size_t kMaxMessageChunkSize = IPC::Channel::kMaximumMessageSize / 4;
 
 // static
 CefDevToolsFrontend* CefDevToolsFrontend::Show(
-    CefRefPtr<CefBrowserHostImpl> inspected_browser,
+    CefBrowserHostImpl* inspected_browser,
     const CefWindowInfo& windowInfo,
     CefRefPtr<CefClient> client,
     const CefBrowserSettings& settings,
-    const CefPoint& inspect_element_at) {
+    const CefPoint& inspect_element_at,
+    base::OnceClosure frontend_destroyed_callback) {
   CefBrowserSettings new_settings = settings;
   if (!windowInfo.windowless_rendering_enabled &&
       CefColorGetA(new_settings.background_color) != SK_AlphaOPAQUE) {
@@ -187,7 +265,8 @@ CefDevToolsFrontend* CefDevToolsFrontend::Show(
   // destroyed.
   CefDevToolsFrontend* devtools_frontend = new CefDevToolsFrontend(
       static_cast<CefBrowserHostImpl*>(frontend_browser.get()),
-      inspected_contents, inspect_element_at);
+      inspected_contents, inspect_element_at,
+      std::move(frontend_destroyed_callback));
 
   // Need to load the URL after creating the DevTools objects.
   frontend_browser->GetMainFrame()->LoadURL(GetFrontendURL());
@@ -216,23 +295,23 @@ void CefDevToolsFrontend::Close() {
                             frontend_browser_.get(), true));
 }
 
-void CefDevToolsFrontend::DisconnectFromTarget() {
-  if (!agent_host_)
-    return;
-  agent_host_->DetachClient(this);
-  agent_host_ = nullptr;
-}
-
 CefDevToolsFrontend::CefDevToolsFrontend(
-    CefRefPtr<CefBrowserHostImpl> frontend_browser,
+    CefBrowserHostImpl* frontend_browser,
     content::WebContents* inspected_contents,
-    const CefPoint& inspect_element_at)
+    const CefPoint& inspect_element_at,
+    base::OnceClosure frontend_destroyed_callback)
     : content::WebContentsObserver(frontend_browser->web_contents()),
       frontend_browser_(frontend_browser),
       inspected_contents_(inspected_contents),
       inspect_element_at_(inspect_element_at),
-      file_manager_(frontend_browser.get(), GetPrefs()),
+      frontend_destroyed_callback_(std::move(frontend_destroyed_callback)),
-      weak_factory_(this) {}
+      file_manager_(frontend_browser, GetPrefs()),
+      protocol_log_file_(
+          base::CommandLine::ForCurrentProcess()->GetSwitchValuePath(
+              switches::kDevToolsProtocolLogFile)),
+      weak_factory_(this) {
+  DCHECK(!frontend_destroyed_callback_.is_null());
+}
 
 CefDevToolsFrontend::~CefDevToolsFrontend() {}
 
@@ -279,6 +358,7 @@ void CefDevToolsFrontend::WebContentsDestroyed() {
     agent_host_->DetachClient(this);
     agent_host_ = nullptr;
   }
+  std::move(frontend_destroyed_callback_).Run();
   delete this;
 }
 
@@ -300,6 +380,9 @@ void CefDevToolsFrontend::HandleMessageFromDevToolsFrontend(
     std::string protocol_message;
     if (!agent_host_ || !params->GetString(0, &protocol_message))
       return;
+    if (ProtocolLoggingEnabled()) {
+      LogProtocolMessage(ProtocolMessageType::METHOD, protocol_message);
+    }
     agent_host_->DispatchProtocolMessage(
         this, base::as_bytes(base::make_span(protocol_message)));
   } else if (method == "loadCompleted") {
@@ -451,6 +534,14 @@ void CefDevToolsFrontend::DispatchProtocolMessage(
     base::span<const uint8_t> message) {
   base::StringPiece str_message(reinterpret_cast<const char*>(message.data()),
                                 message.size());
+  if (ProtocolLoggingEnabled()) {
+    // Quick check to avoid parsing the JSON object. Events begin with a
+    // "method" value whereas method results begin with an "id" value.
+    LogProtocolMessage(str_message.starts_with("{\"method\":")
+                           ? ProtocolMessageType::EVENT
+                           : ProtocolMessageType::RESULT,
+                       str_message);
+  }
   if (str_message.length() < kMaxMessageChunkSize) {
     std::string param;
     base::EscapeJSONString(str_message, true, &param);
@@ -504,6 +595,23 @@ void CefDevToolsFrontend::SendMessageAck(int request_id,
   CallClientFunction("DevToolsAPI.embedderMessageAck", &id_value, arg, nullptr);
 }
 
+bool CefDevToolsFrontend::ProtocolLoggingEnabled() const {
+  return !protocol_log_file_.empty();
+}
+
+void CefDevToolsFrontend::LogProtocolMessage(ProtocolMessageType type,
+                                             const base::StringPiece& message) {
+  DCHECK(ProtocolLoggingEnabled());
+
+  std::string to_log = message.substr(0, kMaxLogLineLength).as_string();
+
+  // Execute in an ordered context that allows blocking.
+  auto task_runner = CefContentBrowserClient::Get()->background_task_runner();
+  task_runner->PostTask(
+      FROM_HERE, base::BindOnce(::LogProtocolMessage, protocol_log_file_, type,
+                                std::move(to_log)));
+}
+
 void CefDevToolsFrontend::AgentHostClosed(
     content::DevToolsAgentHost* agent_host) {
   DCHECK(agent_host == agent_host_.get());

libcef/browser/devtools/devtools_frontend.h

@@ -11,6 +11,7 @@
 #include "libcef/browser/devtools/devtools_file_manager.h"
 
 #include "base/compiler_specific.h"
+#include "base/files/file_path.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
@@ -31,36 +32,38 @@ class WebContents;
 
 class PrefService;
 
+enum class ProtocolMessageType {
+  METHOD,
+  RESULT,
+  EVENT,
+};
+
 class CefDevToolsFrontend : public content::WebContentsObserver,
                             public content::DevToolsAgentHostClient {
  public:
   static CefDevToolsFrontend* Show(
-      CefRefPtr<CefBrowserHostImpl> inspected_browser,
+      CefBrowserHostImpl* inspected_browser,
       const CefWindowInfo& windowInfo,
       CefRefPtr<CefClient> client,
       const CefBrowserSettings& settings,
-      const CefPoint& inspect_element_at);
+      const CefPoint& inspect_element_at,
+      base::OnceClosure frontend_destroyed_callback);
 
   void Activate();
   void Focus();
   void InspectElementAt(int x, int y);
   void Close();
 
-  void DisconnectFromTarget();
-
   void CallClientFunction(const std::string& function_name,
                           const base::Value* arg1,
                           const base::Value* arg2,
                           const base::Value* arg3);
 
-  CefRefPtr<CefBrowserHostImpl> frontend_browser() const {
-    return frontend_browser_;
-  }
-
  private:
-  CefDevToolsFrontend(CefRefPtr<CefBrowserHostImpl> frontend_browser,
+  CefDevToolsFrontend(CefBrowserHostImpl* frontend_browser,
                       content::WebContents* inspected_contents,
-                      const CefPoint& inspect_element_at);
+                      const CefPoint& inspect_element_at,
+                      base::OnceClosure destroyed_callback);
   ~CefDevToolsFrontend() override;
 
   // content::DevToolsAgentHostClient implementation.
@@ -78,12 +81,17 @@ class CefDevToolsFrontend : public content::WebContentsObserver,
 
   void SendMessageAck(int request_id, const base::Value* arg1);
 
+  bool ProtocolLoggingEnabled() const;
+  void LogProtocolMessage(ProtocolMessageType type,
+                          const base::StringPiece& message);
+
   PrefService* GetPrefs() const;
 
   CefRefPtr<CefBrowserHostImpl> frontend_browser_;
   content::WebContents* inspected_contents_;
   scoped_refptr<content::DevToolsAgentHost> agent_host_;
   CefPoint inspect_element_at_;
+  base::OnceClosure frontend_destroyed_callback_;
   std::unique_ptr<content::DevToolsFrontendHost> frontend_host_;
 
   class NetworkResourceLoader;
@@ -93,6 +101,9 @@ class CefDevToolsFrontend : public content::WebContentsObserver,
   using ExtensionsAPIs = std::map<std::string, std::string>;
   ExtensionsAPIs extensions_api_;
   CefDevToolsFileManager file_manager_;
+
+  const base::FilePath protocol_log_file_;
+
   base::WeakPtrFactory<CefDevToolsFrontend> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CefDevToolsFrontend);

libcef/browser/devtools/devtools_manager.cc

@@ -0,0 +1,200 @@
+// Copyright (c) 2020 The Chromium Embedded Framework Authors. All rights
+// reserved. Use of this source code is governed by a BSD-style license that
+// can be found in the LICENSE file.
+
+#include "libcef/browser/devtools/devtools_manager.h"
+
+#include "libcef/browser/devtools/devtools_controller.h"
+#include "libcef/browser/devtools/devtools_frontend.h"
+
+#include "content/public/browser/web_contents.h"
+
+namespace {
+
+// May be created on any thread but will be destroyed on the UI thread.
+class CefDevToolsRegistrationImpl : public CefRegistration,
+                                    public CefDevToolsController::Observer {
+ public:
+  explicit CefDevToolsRegistrationImpl(
+      CefRefPtr<CefDevToolsMessageObserver> observer)
+      : observer_(observer) {
+    DCHECK(observer_);
+  }
+
+  ~CefDevToolsRegistrationImpl() override {
+    CEF_REQUIRE_UIT();
+
+    // May be null if OnDevToolsControllerDestroyed was called.
+    if (!controller_)
+      return;
+
+    controller_->RemoveObserver(this);
+  }
+
+  void Initialize(CefBrowserHostImpl* browser,
+                  base::WeakPtr<CefDevToolsController> controller) {
+    CEF_REQUIRE_UIT();
+    DCHECK(browser && controller);
+    DCHECK(!browser_ && !controller_);
+    browser_ = browser;
+    controller_ = controller;
+
+    controller_->AddObserver(this);
+  }
+
+ private:
+  // CefDevToolsController::Observer methods:
+  bool OnDevToolsMessage(const base::StringPiece& message) override {
+    CEF_REQUIRE_UIT();
+    return observer_->OnDevToolsMessage(browser_, message.data(),
+                                        message.size());
+  }
+
+  void OnDevToolsMethodResult(int message_id,
+                              bool success,
+                              const base::StringPiece& result) override {
+    CEF_REQUIRE_UIT();
+    observer_->OnDevToolsMethodResult(browser_, message_id, success,
+                                      result.data(), result.size());
+  }
+
+  void OnDevToolsEvent(const base::StringPiece& method,
+                       const base::StringPiece& params) override {
+    CEF_REQUIRE_UIT();
+    observer_->OnDevToolsEvent(browser_, method.as_string(), params.data(),
+                               params.size());
+  }
+
+  void OnDevToolsAgentAttached() override {
+    CEF_REQUIRE_UIT();
+    observer_->OnDevToolsAgentAttached(browser_);
+  }
+
+  void OnDevToolsAgentDetached() override {
+    CEF_REQUIRE_UIT();
+    observer_->OnDevToolsAgentDetached(browser_);
+  }
+
+  void OnDevToolsControllerDestroyed() override {
+    CEF_REQUIRE_UIT();
+    browser_ = nullptr;
+    controller_.reset();
+  }
+
+  CefRefPtr<CefDevToolsMessageObserver> observer_;
+
+  CefBrowserHostImpl* browser_ = nullptr;
+  base::WeakPtr<CefDevToolsController> controller_;
+
+  IMPLEMENT_REFCOUNTING_DELETE_ON_UIT(CefDevToolsRegistrationImpl);
+  DISALLOW_COPY_AND_ASSIGN(CefDevToolsRegistrationImpl);
+};
+
+}  // namespace
+
+CefDevToolsManager::CefDevToolsManager(CefBrowserHostImpl* inspected_browser)
+    : inspected_browser_(inspected_browser), weak_ptr_factory_(this) {
+  CEF_REQUIRE_UIT();
+}
+
+CefDevToolsManager::~CefDevToolsManager() {
+  CEF_REQUIRE_UIT();
+}
+
+void CefDevToolsManager::ShowDevTools(const CefWindowInfo& windowInfo,
+                                      CefRefPtr<CefClient> client,
+                                      const CefBrowserSettings& settings,
+                                      const CefPoint& inspect_element_at) {
+  CEF_REQUIRE_UIT();
+  if (devtools_frontend_) {
+    if (!inspect_element_at.IsEmpty()) {
+      devtools_frontend_->InspectElementAt(inspect_element_at.x,
+                                           inspect_element_at.y);
+    }
+    devtools_frontend_->Focus();
+    return;
+  }
+
+  devtools_frontend_ = CefDevToolsFrontend::Show(
+      inspected_browser_, windowInfo, client, settings, inspect_element_at,
+      base::BindOnce(&CefDevToolsManager::OnFrontEndDestroyed,
+                     weak_ptr_factory_.GetWeakPtr()));
+}
+
+void CefDevToolsManager::CloseDevTools() {
+  CEF_REQUIRE_UIT();
+  if (!devtools_frontend_)
+    return;
+  devtools_frontend_->Close();
+}
+
+bool CefDevToolsManager::HasDevTools() {
+  CEF_REQUIRE_UIT();
+  return !!devtools_frontend_;
+}
+
+bool CefDevToolsManager::SendDevToolsMessage(const void* message,
+                                             size_t message_size) {
+  CEF_REQUIRE_UIT();
+  if (!message || message_size == 0)
+    return false;
+
+  if (!EnsureController())
+    return false;
+
+  return devtools_controller_->SendDevToolsMessage(
+      base::StringPiece(static_cast<const char*>(message), message_size));
+}
+
+int CefDevToolsManager::ExecuteDevToolsMethod(
+    int message_id,
+    const CefString& method,
+    CefRefPtr<CefDictionaryValue> params) {
+  CEF_REQUIRE_UIT();
+  if (method.empty())
+    return 0;
+
+  if (!EnsureController())
+    return 0;
+
+  if (params && params->IsValid()) {
+    CefDictionaryValueImpl* impl =
+        static_cast<CefDictionaryValueImpl*>(params.get());
+    CefValueController::AutoLock lock_scope(impl->controller());
+    return devtools_controller_->ExecuteDevToolsMethod(message_id, method,
+                                                       impl->GetValueUnsafe());
+  } else {
+    return devtools_controller_->ExecuteDevToolsMethod(message_id, method,
+                                                       nullptr);
+  }
+}
+
+// static
+CefRefPtr<CefRegistration> CefDevToolsManager::CreateRegistration(
+    CefRefPtr<CefDevToolsMessageObserver> observer) {
+  DCHECK(observer);
+  return new CefDevToolsRegistrationImpl(observer);
+}
+
+void CefDevToolsManager::InitializeRegistrationOnUIThread(
+    CefRefPtr<CefRegistration> registration) {
+  CEF_REQUIRE_UIT();
+
+  if (!EnsureController())
+    return;
+
+  static_cast<CefDevToolsRegistrationImpl*>(registration.get())
+      ->Initialize(inspected_browser_, devtools_controller_->GetWeakPtr());
+}
+
+void CefDevToolsManager::OnFrontEndDestroyed() {
+  devtools_frontend_ = nullptr;
+}
+
+bool CefDevToolsManager::EnsureController() {
+  if (!devtools_controller_) {
+    devtools_controller_.reset(
+        new CefDevToolsController(inspected_browser_->web_contents()));
+  }
+  return true;
+}

libcef/browser/devtools/devtools_manager.h

@@ -0,0 +1,69 @@
+// Copyright (c) 2020 The Chromium Embedded Framework Authors. All rights
+// reserved. Use of this source code is governed by a BSD-style license that
+// can be found in the LICENSE file.
+
+#ifndef CEF_LIBCEF_BROWSER_DEVTOOLS_DEVTOOLS_MANAGER_H_
+#define CEF_LIBCEF_BROWSER_DEVTOOLS_DEVTOOLS_MANAGER_H_
+#pragma once
+
+#include "include/cef_browser.h"
+
+#include "base/memory/weak_ptr.h"
+
+class CefBrowserHostImpl;
+class CefDevToolsController;
+class CefDevToolsFrontend;
+
+namespace content {
+class WebContents;
+}
+
+// Manages DevTools instances. Methods must be called on the UI thread unless
+// otherwise indicated.
+class CefDevToolsManager {
+ public:
+  // |inspected_browser| will outlive this object.
+  explicit CefDevToolsManager(CefBrowserHostImpl* inspected_browser);
+  ~CefDevToolsManager();
+
+  // See CefBrowserHost methods of the same name for documentation.
+  void ShowDevTools(const CefWindowInfo& windowInfo,
+                    CefRefPtr<CefClient> client,
+                    const CefBrowserSettings& settings,
+                    const CefPoint& inspect_element_at);
+  void CloseDevTools();
+  bool HasDevTools();
+  bool SendDevToolsMessage(const void* message, size_t message_size);
+  int ExecuteDevToolsMethod(int message_id,
+                            const CefString& method,
+                            CefRefPtr<CefDictionaryValue> param);
+
+  // These methods are used to implement
+  // CefBrowserHost::AddDevToolsMessageObserver. CreateRegistration is safe to
+  // call on any thread. InitializeRegistrationOnUIThread should be called
+  // immediately afterwards on the UI thread.
+  static CefRefPtr<CefRegistration> CreateRegistration(
+      CefRefPtr<CefDevToolsMessageObserver> observer);
+  void InitializeRegistrationOnUIThread(
+      CefRefPtr<CefRegistration> registration);
+
+ private:
+  void OnFrontEndDestroyed();
+
+  bool EnsureController();
+
+  CefBrowserHostImpl* const inspected_browser_;
+
+  // CefDevToolsFrontend will delete itself when the frontend WebContents is
+  // destroyed.
+  CefDevToolsFrontend* devtools_frontend_ = nullptr;
+
+  // Used for sending DevTools protocol messages without an active frontend.
+  std::unique_ptr<CefDevToolsController> devtools_controller_;
+
+  base::WeakPtrFactory<CefDevToolsManager> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(CefDevToolsManager);
+};
+
+#endif  // CEF_LIBCEF_BROWSER_DEVTOOLS_DEVTOOLS_MANAGER_H_

libcef/browser/devtools/devtools_util.cc

@@ -0,0 +1,131 @@
+// Copyright (c) 2020 The Chromium Embedded Framework Authors. All rights
+// reserved. Use of this source code is governed by a BSD-style license that
+// can be found in the LICENSE file.
+
+#include "libcef/browser/devtools/devtools_util.h"
+
+#include "base/strings/string_number_conversions.h"
+
+namespace devtools_util {
+
+namespace {
+
+bool IsValidDictionary(const base::StringPiece& str, bool allow_empty) {
+  return str.length() >= (allow_empty ? 2 : 3) && str[0] == '{' &&
+         str[str.length() - 1] == '}';
+}
+
+// Example:
+// {"method":"Target.targetDestroyed","params":{"targetId":"1234..."}}
+bool ParseEvent(const base::StringPiece& message,
+                base::StringPiece& method,
+                base::StringPiece& params) {
+  static const char kMethodStart[] = "{\"method\":\"";
+  static const char kMethodEnd[] = "\"";
+  static const char kParamsStart[] = ",\"params\":";
+
+  if (!message.starts_with(kMethodStart))
+    return false;
+
+  const size_t method_start = sizeof(kMethodStart) - 1;
+  const size_t method_end = message.find(kMethodEnd, method_start);
+  if (method_end < 0U)
+    return false;
+  method = message.substr(method_start, method_end - method_start);
+  if (method.empty())
+    return false;
+
+  size_t remainder_start = method_end + sizeof(kMethodEnd) - 1;
+  if (remainder_start == message.size() - 1) {
+    // No more contents.
+    params = base::StringPiece();
+  } else {
+    const base::StringPiece& remainder = message.substr(remainder_start);
+    if (remainder.starts_with(kParamsStart)) {
+      // Stop immediately before the message closing bracket.
+      remainder_start += sizeof(kParamsStart) - 1;
+      params =
+          message.substr(remainder_start, message.size() - 1 - remainder_start);
+    } else {
+      // Invalid format.
+      return false;
+    }
+
+    if (!IsValidDictionary(params, /*allow_empty=*/true))
+      return false;
+  }
+
+  return true;
+}
+
+// Examples:
+// {"id":3,"result":{}}
+// {"id":4,"result":{"debuggerId":"-2193881606781505058.81393575456727957"}}
+// {"id":5,"error":{"code":-32000,"message":"Not supported"}}
+bool ParseResult(const base::StringPiece& message,
+                 int& message_id,
+                 bool& success,
+                 base::StringPiece& result) {
+  static const char kIdStart[] = "{\"id\":";
+  static const char kIdEnd[] = ",";
+  static const char kResultStart[] = "\"result\":";
+  static const char kErrorStart[] = "\"error\":";
+
+  if (!message.starts_with(kIdStart))
+    return false;
+
+  const size_t id_start = sizeof(kIdStart) - 1;
+  const size_t id_end = message.find(kIdEnd, id_start);
+  if (id_end < 0U)
+    return false;
+  const base::StringPiece& id_str = message.substr(id_start, id_end - id_start);
+  if (id_str.empty() || !base::StringToInt(id_str, &message_id))
+    return false;
+
+  size_t remainder_start = id_end + sizeof(kIdEnd) - 1;
+  const base::StringPiece& remainder = message.substr(remainder_start);
+  if (remainder.starts_with(kResultStart)) {
+    // Stop immediately before the message closing bracket.
+    remainder_start += sizeof(kResultStart) - 1;
+    result =
+        message.substr(remainder_start, message.size() - 1 - remainder_start);
+    success = true;
+  } else if (remainder.starts_with(kErrorStart)) {
+    // Stop immediately before the message closing bracket.
+    remainder_start += sizeof(kErrorStart) - 1;
+    result =
+        message.substr(remainder_start, message.size() - 1 - remainder_start);
+    success = false;
+  } else {
+    // Invalid format.
+    return false;
+  }
+
+  if (!IsValidDictionary(result, /*allow_empty=*/true))
+    return false;
+
+  return true;
+}
+
+}  // namespace
+
+// static
+bool ProtocolParser::IsValidMessage(const base::StringPiece& message) {
+  return IsValidDictionary(message, /*allow_empty=*/false);
+}
+
+bool ProtocolParser::Initialize(const base::StringPiece& message) {
+  if (status_ != UNINITIALIZED)
+    return false;
+
+  if (ParseEvent(message, method_, params_)) {
+    status_ = EVENT;
+  } else if (ParseResult(message, message_id_, success_, params_)) {
+    status_ = RESULT;
+  } else {
+    status_ = FAILURE;
+  }
+  return true;
+}
+
+}  // namespace devtools_util

libcef/browser/devtools/devtools_util.h

@@ -0,0 +1,72 @@
+// Copyright (c) 2020 The Chromium Embedded Framework Authors. All rights
+// reserved. Use of this source code is governed by a BSD-style license that
+// can be found in the LICENSE file.
+
+#ifndef CEF_LIBCEF_BROWSER_DEVTOOLS_DEVTOOLS_UTIL_H_
+#define CEF_LIBCEF_BROWSER_DEVTOOLS_DEVTOOLS_UTIL_H_
+#pragma once
+
+#include "base/strings/string_piece.h"
+
+namespace devtools_util {
+
+// Fast parser for DevTools JSON protocol messages. This implementation makes
+// certain assumptions about the JSON object structure (value order and
+// formatting) to avoid stateful parsing of messages that may be large
+// (sometimes > 1MB in size). The message must be a JSON dictionary that starts
+// with a "method" or "id" value which is non-empty and of the expected data
+// type. Messages that have a "method" value (event message) may optionally have
+// a "params" dictionary. Messages that have an "id" value (result message) must
+// have a "result" or "error" dictionary. The dictionary contents are not
+// validated and may be empty ("{}").
+//
+// Example event message:
+// {"method":"Target.targetDestroyed","params":{"targetId":"1234..."}}
+//
+// Example result messages:
+// {"id":3,"result":{}}
+// {"id":4,"result":{"debuggerId":"-2193881606781505058.81393575456727957"}}
+// {"id":5,"error":{"code":-32000,"message":"Not supported"}}
+struct ProtocolParser {
+  ProtocolParser() = default;
+
+  // Checks for a non-empty JSON dictionary.
+  static bool IsValidMessage(const base::StringPiece& message);
+
+  // Returns false if already initialized.
+  bool Initialize(const base::StringPiece& message);
+
+  bool IsInitialized() const { return status_ != UNINITIALIZED; }
+  bool IsEvent() const { return status_ == EVENT; }
+  bool IsResult() const { return status_ == RESULT; }
+  bool IsFailure() const { return status_ == FAILURE; }
+
+  void Reset() { status_ = UNINITIALIZED; }
+
+  // For event messages:
+  //   "method" string:
+  base::StringPiece method_;
+
+  // For result messages:
+  //   "id" int:
+  int message_id_ = 0;
+  //   true if "result" value, false if "error" value:
+  bool success_ = false;
+
+  // For both:
+  //   "params", "result" or "error" dictionary:
+  base::StringPiece params_;
+
+ private:
+  enum Status {
+    UNINITIALIZED,
+    EVENT,    // Event message.
+    RESULT,   // Result message.
+    FAILURE,  // Parsing failure.
+  };
+  Status status_ = UNINITIALIZED;
+};
+
+}  // namespace devtools_util
+
+#endif  // CEF_LIBCEF_BROWSER_DEVTOOLS_DEVTOOLS_UTIL_H_

libcef/browser/devtools/devtools_util_unittest.cc

@@ -0,0 +1,204 @@
+// Copyright (c) 2020 The Chromium Embedded Framework Authors. All rights
+// reserved. Use of this source code is governed by a BSD-style license that
+// can be found in the LICENSE file.
+
+#include "libcef/browser/devtools/devtools_util.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+using namespace devtools_util;
+
+TEST(DevToolsUtil, ProtocolParser_IsValidMessage) {
+  // Empty dictionary is not valid.
+  EXPECT_FALSE(ProtocolParser::IsValidMessage(""));
+  EXPECT_FALSE(ProtocolParser::IsValidMessage("{}"));
+
+  // Incorrectly formatted dictionary is not valid.
+  EXPECT_FALSE(ProtocolParser::IsValidMessage("{ ]"));
+
+  // Everything else is valid (we don't verify JSON structure).
+  EXPECT_TRUE(ProtocolParser::IsValidMessage("{ }"));
+  EXPECT_TRUE(ProtocolParser::IsValidMessage("{blah blah}"));
+  EXPECT_TRUE(ProtocolParser::IsValidMessage("{method:\"foobar\"}"));
+}
+
+TEST(DevToolsUtil, ProtocolParser_Initialize_IsFailure_Unknown) {
+  ProtocolParser parser;
+  EXPECT_FALSE(parser.IsInitialized());
+
+  // Empty message is invalid.
+  EXPECT_TRUE(parser.Initialize(""));
+  EXPECT_TRUE(parser.IsInitialized());
+  EXPECT_TRUE(parser.IsFailure());
+
+  parser.Reset();
+  EXPECT_FALSE(parser.IsInitialized());
+
+  // Empty dictionary is invalid.
+  EXPECT_TRUE(parser.Initialize("{}"));
+  EXPECT_TRUE(parser.IsInitialized());
+  EXPECT_TRUE(parser.IsFailure());
+
+  parser.Reset();
+  EXPECT_FALSE(parser.IsInitialized());
+
+  // Unrecognized dictionary type is invalid.
+  EXPECT_TRUE(parser.Initialize("{blah blah}"));
+  EXPECT_TRUE(parser.IsInitialized());
+  EXPECT_TRUE(parser.IsFailure());
+}
+
+TEST(DevToolsUtil, ProtocolParser_Initialize_IsFailure_EventMalformed) {
+  ProtocolParser parser;
+  EXPECT_FALSE(parser.IsInitialized());
+
+  // Empty method is invalid.
+  EXPECT_TRUE(parser.Initialize("{\"method\":\"\"}"));
+  EXPECT_TRUE(parser.IsInitialized());
+  EXPECT_TRUE(parser.IsFailure());
+
+  parser.Reset();
+  EXPECT_FALSE(parser.IsInitialized());
+
+  // Unrecognized value is invalid.
+  EXPECT_TRUE(parser.Initialize("{\"method\":\"foo\",oops:false}"));
+  EXPECT_TRUE(parser.IsInitialized());
+  EXPECT_TRUE(parser.IsFailure());
+
+  parser.Reset();
+  EXPECT_FALSE(parser.IsInitialized());
+
+  // Params must be a dictionary.
+  EXPECT_TRUE(parser.Initialize("{\"method\":\",params:[]}"));
+  EXPECT_TRUE(parser.IsInitialized());
+  EXPECT_TRUE(parser.IsFailure());
+}
+
+TEST(DevToolsUtil, ProtocolParser_Initialize_IsEvent) {
+  ProtocolParser parser;
+  EXPECT_FALSE(parser.IsInitialized());
+
+  // Method without params is valid.
+  std::string message = "{\"method\":\"Test.myMethod\"}";
+  EXPECT_TRUE(parser.Initialize(message));
+  EXPECT_TRUE(parser.IsInitialized());
+  EXPECT_TRUE(parser.IsEvent());
+  EXPECT_STREQ("Test.myMethod", parser.method_.as_string().data());
+  EXPECT_TRUE(parser.params_.empty());
+
+  parser.Reset();
+  EXPECT_FALSE(parser.IsInitialized());
+
+  // Method with empty params dictionary is valid.
+  message = "{\"method\":\"Test.myMethod2\",\"params\":{}}";
+  EXPECT_TRUE(parser.Initialize(message));
+  EXPECT_TRUE(parser.IsInitialized());
+  EXPECT_TRUE(parser.IsEvent());
+  EXPECT_STREQ("Test.myMethod2", parser.method_.as_string().data());
+  EXPECT_STREQ("{}", parser.params_.as_string().data());
+
+  parser.Reset();
+  EXPECT_FALSE(parser.IsInitialized());
+
+  // Method with non-empty params dictionary is valid.
+  message = "{\"method\":\"Test.myMethod3\",\"params\":{\"foo\":\"bar\"}}";
+  EXPECT_TRUE(parser.Initialize(message));
+  EXPECT_TRUE(parser.IsInitialized());
+  EXPECT_TRUE(parser.IsEvent());
+  EXPECT_STREQ("Test.myMethod3", parser.method_.as_string().data());
+  EXPECT_STREQ("{\"foo\":\"bar\"}", parser.params_.as_string().data());
+}
+
+TEST(DevToolsUtil, ProtocolParser_Initialize_IsFailure_ResultMalformed) {
+  ProtocolParser parser;
+  EXPECT_FALSE(parser.IsInitialized());
+
+  // Empty ID is invalid.
+  EXPECT_TRUE(parser.Initialize("{\"id\":,result:{}}"));
+  EXPECT_TRUE(parser.IsInitialized());
+  EXPECT_TRUE(parser.IsFailure());
+
+  parser.Reset();
+  EXPECT_FALSE(parser.IsInitialized());
+
+  // Missing result or error value is invalid.
+  EXPECT_TRUE(parser.Initialize("{\"id\":1}"));
+  EXPECT_TRUE(parser.IsInitialized());
+  EXPECT_TRUE(parser.IsFailure());
+
+  parser.Reset();
+  EXPECT_FALSE(parser.IsInitialized());
+
+  // Unrecognized value is invalid.
+  EXPECT_TRUE(parser.Initialize("{\"id\":1,oops:false}"));
+  EXPECT_TRUE(parser.IsInitialized());
+  EXPECT_TRUE(parser.IsFailure());
+
+  parser.Reset();
+  EXPECT_FALSE(parser.IsInitialized());
+
+  // Result must be a dictionary.
+  EXPECT_TRUE(parser.Initialize("{\"id\":1,\"result\":[]}"));
+  EXPECT_TRUE(parser.IsInitialized());
+  EXPECT_TRUE(parser.IsFailure());
+
+  parser.Reset();
+  EXPECT_FALSE(parser.IsInitialized());
+
+  // Error must be a dictionary.
+  EXPECT_TRUE(parser.Initialize("{\"id\":1,\"error\":[]}"));
+  EXPECT_TRUE(parser.IsInitialized());
+  EXPECT_TRUE(parser.IsFailure());
+}
+
+TEST(DevToolsUtil, ProtocolParser_Initialize_IsResult_Result) {
+  ProtocolParser parser;
+  EXPECT_FALSE(parser.IsInitialized());
+
+  // Id with empty result dictionary is valid.
+  std::string message = "{\"id\":1,\"result\":{}}";
+  EXPECT_TRUE(parser.Initialize(message));
+  EXPECT_TRUE(parser.IsInitialized());
+  EXPECT_TRUE(parser.IsResult());
+  EXPECT_EQ(1, parser.message_id_);
+  EXPECT_TRUE(parser.success_);
+  EXPECT_STREQ("{}", parser.params_.as_string().data());
+
+  parser.Reset();
+  EXPECT_FALSE(parser.IsInitialized());
+
+  // Id with non-empty result dictionary is valid.
+  message = "{\"id\":2,\"result\":{\"foo\":\"bar\"}}";
+  EXPECT_TRUE(parser.Initialize(message));
+  EXPECT_TRUE(parser.IsInitialized());
+  EXPECT_TRUE(parser.IsResult());
+  EXPECT_EQ(2, parser.message_id_);
+  EXPECT_TRUE(parser.success_);
+  EXPECT_STREQ("{\"foo\":\"bar\"}", parser.params_.as_string().data());
+}
+
+TEST(DevToolsUtil, ProtocolParser_Initialize_IsResult_Error) {
+  ProtocolParser parser;
+  EXPECT_FALSE(parser.IsInitialized());
+
+  // Id with empty error dictionary is valid.
+  std::string message = "{\"id\":1,\"error\":{}}";
+  EXPECT_TRUE(parser.Initialize(message));
+  EXPECT_TRUE(parser.IsInitialized());
+  EXPECT_TRUE(parser.IsResult());
+  EXPECT_EQ(1, parser.message_id_);
+  EXPECT_FALSE(parser.success_);
+  EXPECT_STREQ("{}", parser.params_.as_string().data());
+
+  parser.Reset();
+  EXPECT_FALSE(parser.IsInitialized());
+
+  // Id with non-empty error dictionary is valid.
+  message = "{\"id\":2,\"error\":{\"foo\":\"bar\"}}";
+  EXPECT_TRUE(parser.Initialize(message));
+  EXPECT_TRUE(parser.IsInitialized());
+  EXPECT_TRUE(parser.IsResult());
+  EXPECT_EQ(2, parser.message_id_);
+  EXPECT_FALSE(parser.success_);
+  EXPECT_STREQ("{\"foo\":\"bar\"}", parser.params_.as_string().data());
+}

libcef/common/cef_switches.cc

@@ -114,11 +114,13 @@ const char kPluginPolicy_Block[] = "block";
 const char kEnablePreferenceTesting[] = "enable-preference-testing";
 
 // Enable print preview.
-extern const char kEnablePrintPreview[] = "enable-print-preview";
+const char kEnablePrintPreview[] = "enable-print-preview";
 
 // Disable the timeout for delivering new browser info to the renderer process.
-extern const char kDisableNewBrowserInfoTimeout[] =
+const char kDisableNewBrowserInfoTimeout[] = "disable-new-browser-info-timeout";
-    "disable-new-browser-info-timeout";
+
+// File used for logging DevTools protocol messages.
+const char kDevToolsProtocolLogFile[] = "devtools-protocol-log-file";
 
 #if defined(OS_MACOSX)
 // Path to the framework directory.

libcef/common/cef_switches.h

@@ -53,6 +53,7 @@ extern const char kPluginPolicy_Block[];
 extern const char kEnablePreferenceTesting[];
 extern const char kEnablePrintPreview[];
 extern const char kDisableNewBrowserInfoTimeout[];
+extern const char kDevToolsProtocolLogFile[];
 
 #if defined(OS_MACOSX)
 extern const char kFrameworkDirPath[];

libcef/common/json_impl.cc

@@ -34,8 +34,17 @@ int GetJSONWriterOptions(cef_json_writer_options_t options) {
 CefRefPtr<CefValue> CefParseJSON(const CefString& json_string,
                                  cef_json_parser_options_t options) {
   const std::string& json = json_string.ToString();
-  base::Optional<base::Value> parse_result =
+  return CefParseJSON(json.data(), json.size(), options);
-      base::JSONReader::Read(json, GetJSONReaderOptions(options));
+}
+
+CefRefPtr<CefValue> CefParseJSON(const void* json,
+                                 size_t json_size,
+                                 cef_json_parser_options_t options) {
+  if (!json || json_size == 0)
+    return nullptr;
+  base::Optional<base::Value> parse_result = base::JSONReader::Read(
+      base::StringPiece(static_cast<const char*>(json), json_size),
+      GetJSONReaderOptions(options));
   if (parse_result) {
     return new CefValueImpl(
         base::Value::ToUniquePtrValue(std::move(parse_result.value()))

libcef_dll/cpptoc/browser_host_cpptoc.cc

@@ -9,7 +9,7 @@
 // implementations. See the translator.README.txt file in the tools directory
 // for more information.
 //
-// $hash=a84451b4f759f2a4a0fe673d90be1fb5053bfd1a$
+// $hash=516b55b7ea53e2de2b096e85ba0eb83f2a2693f3$
 //
 
 #include "libcef_dll/cpptoc/browser_host_cpptoc.h"
@@ -18,8 +18,10 @@
 #include "libcef_dll/cpptoc/drag_data_cpptoc.h"
 #include "libcef_dll/cpptoc/extension_cpptoc.h"
 #include "libcef_dll/cpptoc/navigation_entry_cpptoc.h"
+#include "libcef_dll/cpptoc/registration_cpptoc.h"
 #include "libcef_dll/cpptoc/request_context_cpptoc.h"
 #include "libcef_dll/ctocpp/client_ctocpp.h"
+#include "libcef_dll/ctocpp/dev_tools_message_observer_ctocpp.h"
 #include "libcef_dll/ctocpp/download_image_callback_ctocpp.h"
 #include "libcef_dll/ctocpp/navigation_entry_visitor_ctocpp.h"
 #include "libcef_dll/ctocpp/pdf_print_callback_ctocpp.h"
@@ -522,6 +524,81 @@ int CEF_CALLBACK browser_host_has_dev_tools(struct _cef_browser_host_t* self) {
   return _retval;
 }
 
+int CEF_CALLBACK
+browser_host_send_dev_tools_message(struct _cef_browser_host_t* self,
+                                    const void* message,
+                                    size_t message_size) {
+  shutdown_checker::AssertNotShutdown();
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  DCHECK(self);
+  if (!self)
+    return 0;
+  // Verify param: message; type: simple_byaddr
+  DCHECK(message);
+  if (!message)
+    return 0;
+
+  // Execute
+  bool _retval = CefBrowserHostCppToC::Get(self)->SendDevToolsMessage(
+      message, message_size);
+
+  // Return type: bool
+  return _retval;
+}
+
+int CEF_CALLBACK
+browser_host_execute_dev_tools_method(struct _cef_browser_host_t* self,
+                                      int message_id,
+                                      const cef_string_t* method,
+                                      struct _cef_dictionary_value_t* params) {
+  shutdown_checker::AssertNotShutdown();
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  DCHECK(self);
+  if (!self)
+    return 0;
+  // Verify param: method; type: string_byref_const
+  DCHECK(method);
+  if (!method)
+    return 0;
+  // Unverified params: params
+
+  // Execute
+  int _retval = CefBrowserHostCppToC::Get(self)->ExecuteDevToolsMethod(
+      message_id, CefString(method), CefDictionaryValueCppToC::Unwrap(params));
+
+  // Return type: simple
+  return _retval;
+}
+
+struct _cef_registration_t* CEF_CALLBACK
+browser_host_add_dev_tools_message_observer(
+    struct _cef_browser_host_t* self,
+    struct _cef_dev_tools_message_observer_t* observer) {
+  shutdown_checker::AssertNotShutdown();
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  DCHECK(self);
+  if (!self)
+    return NULL;
+  // Verify param: observer; type: refptr_diff
+  DCHECK(observer);
+  if (!observer)
+    return NULL;
+
+  // Execute
+  CefRefPtr<CefRegistration> _retval =
+      CefBrowserHostCppToC::Get(self)->AddDevToolsMessageObserver(
+          CefDevToolsMessageObserverCToCpp::Wrap(observer));
+
+  // Return type: refptr_same
+  return CefRegistrationCppToC::Wrap(_retval);
+}
+
 void CEF_CALLBACK
 browser_host_get_navigation_entries(struct _cef_browser_host_t* self,
                                     cef_navigation_entry_visitor_t* visitor,
@@ -1285,6 +1362,10 @@ CefBrowserHostCppToC::CefBrowserHostCppToC() {
   GetStruct()->show_dev_tools = browser_host_show_dev_tools;
   GetStruct()->close_dev_tools = browser_host_close_dev_tools;
   GetStruct()->has_dev_tools = browser_host_has_dev_tools;
+  GetStruct()->send_dev_tools_message = browser_host_send_dev_tools_message;
+  GetStruct()->execute_dev_tools_method = browser_host_execute_dev_tools_method;
+  GetStruct()->add_dev_tools_message_observer =
+      browser_host_add_dev_tools_message_observer;
   GetStruct()->get_navigation_entries = browser_host_get_navigation_entries;
   GetStruct()->set_mouse_cursor_change_disabled =
       browser_host_set_mouse_cursor_change_disabled;

libcef_dll/cpptoc/dev_tools_message_observer_cpptoc.cc

@@ -0,0 +1,184 @@
+// Copyright (c) 2020 The Chromium Embedded Framework Authors. All rights
+// reserved. Use of this source code is governed by a BSD-style license that
+// can be found in the LICENSE file.
+//
+// ---------------------------------------------------------------------------
+//
+// This file was generated by the CEF translator tool. If making changes by
+// hand only do so within the body of existing method and function
+// implementations. See the translator.README.txt file in the tools directory
+// for more information.
+//
+// $hash=c4a7b4d679f1f2ed47fc31df3e2099962d5cb9d6$
+//
+
+#include "libcef_dll/cpptoc/dev_tools_message_observer_cpptoc.h"
+#include "libcef_dll/ctocpp/browser_ctocpp.h"
+#include "libcef_dll/shutdown_checker.h"
+
+namespace {
+
+// MEMBER FUNCTIONS - Body may be edited by hand.
+
+int CEF_CALLBACK dev_tools_message_observer_on_dev_tools_message(
+    struct _cef_dev_tools_message_observer_t* self,
+    cef_browser_t* browser,
+    const void* message,
+    size_t message_size) {
+  shutdown_checker::AssertNotShutdown();
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  DCHECK(self);
+  if (!self)
+    return 0;
+  // Verify param: browser; type: refptr_diff
+  DCHECK(browser);
+  if (!browser)
+    return 0;
+  // Verify param: message; type: simple_byaddr
+  DCHECK(message);
+  if (!message)
+    return 0;
+
+  // Execute
+  bool _retval = CefDevToolsMessageObserverCppToC::Get(self)->OnDevToolsMessage(
+      CefBrowserCToCpp::Wrap(browser), message, message_size);
+
+  // Return type: bool
+  return _retval;
+}
+
+void CEF_CALLBACK dev_tools_message_observer_on_dev_tools_method_result(
+    struct _cef_dev_tools_message_observer_t* self,
+    cef_browser_t* browser,
+    int message_id,
+    int success,
+    const void* result,
+    size_t result_size) {
+  shutdown_checker::AssertNotShutdown();
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  DCHECK(self);
+  if (!self)
+    return;
+  // Verify param: browser; type: refptr_diff
+  DCHECK(browser);
+  if (!browser)
+    return;
+  // Unverified params: result
+
+  // Execute
+  CefDevToolsMessageObserverCppToC::Get(self)->OnDevToolsMethodResult(
+      CefBrowserCToCpp::Wrap(browser), message_id, success ? true : false,
+      result, result_size);
+}
+
+void CEF_CALLBACK dev_tools_message_observer_on_dev_tools_event(
+    struct _cef_dev_tools_message_observer_t* self,
+    cef_browser_t* browser,
+    const cef_string_t* method,
+    const void* params,
+    size_t params_size) {
+  shutdown_checker::AssertNotShutdown();
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  DCHECK(self);
+  if (!self)
+    return;
+  // Verify param: browser; type: refptr_diff
+  DCHECK(browser);
+  if (!browser)
+    return;
+  // Verify param: method; type: string_byref_const
+  DCHECK(method);
+  if (!method)
+    return;
+  // Unverified params: params
+
+  // Execute
+  CefDevToolsMessageObserverCppToC::Get(self)->OnDevToolsEvent(
+      CefBrowserCToCpp::Wrap(browser), CefString(method), params, params_size);
+}
+
+void CEF_CALLBACK dev_tools_message_observer_on_dev_tools_agent_attached(
+    struct _cef_dev_tools_message_observer_t* self,
+    cef_browser_t* browser) {
+  shutdown_checker::AssertNotShutdown();
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  DCHECK(self);
+  if (!self)
+    return;
+  // Verify param: browser; type: refptr_diff
+  DCHECK(browser);
+  if (!browser)
+    return;
+
+  // Execute
+  CefDevToolsMessageObserverCppToC::Get(self)->OnDevToolsAgentAttached(
+      CefBrowserCToCpp::Wrap(browser));
+}
+
+void CEF_CALLBACK dev_tools_message_observer_on_dev_tools_agent_detached(
+    struct _cef_dev_tools_message_observer_t* self,
+    cef_browser_t* browser) {
+  shutdown_checker::AssertNotShutdown();
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  DCHECK(self);
+  if (!self)
+    return;
+  // Verify param: browser; type: refptr_diff
+  DCHECK(browser);
+  if (!browser)
+    return;
+
+  // Execute
+  CefDevToolsMessageObserverCppToC::Get(self)->OnDevToolsAgentDetached(
+      CefBrowserCToCpp::Wrap(browser));
+}
+
+}  // namespace
+
+// CONSTRUCTOR - Do not edit by hand.
+
+CefDevToolsMessageObserverCppToC::CefDevToolsMessageObserverCppToC() {
+  GetStruct()->on_dev_tools_message =
+      dev_tools_message_observer_on_dev_tools_message;
+  GetStruct()->on_dev_tools_method_result =
+      dev_tools_message_observer_on_dev_tools_method_result;
+  GetStruct()->on_dev_tools_event =
+      dev_tools_message_observer_on_dev_tools_event;
+  GetStruct()->on_dev_tools_agent_attached =
+      dev_tools_message_observer_on_dev_tools_agent_attached;
+  GetStruct()->on_dev_tools_agent_detached =
+      dev_tools_message_observer_on_dev_tools_agent_detached;
+}
+
+// DESTRUCTOR - Do not edit by hand.
+
+CefDevToolsMessageObserverCppToC::~CefDevToolsMessageObserverCppToC() {
+  shutdown_checker::AssertNotShutdown();
+}
+
+template <>
+CefRefPtr<CefDevToolsMessageObserver>
+CefCppToCRefCounted<CefDevToolsMessageObserverCppToC,
+                    CefDevToolsMessageObserver,
+                    cef_dev_tools_message_observer_t>::
+    UnwrapDerived(CefWrapperType type, cef_dev_tools_message_observer_t* s) {
+  NOTREACHED() << "Unexpected class type: " << type;
+  return nullptr;
+}
+
+template <>
+CefWrapperType
+    CefCppToCRefCounted<CefDevToolsMessageObserverCppToC,
+                        CefDevToolsMessageObserver,
+                        cef_dev_tools_message_observer_t>::kWrapperType =
+        WT_DEV_TOOLS_MESSAGE_OBSERVER;

libcef_dll/cpptoc/dev_tools_message_observer_cpptoc.h

@@ -0,0 +1,40 @@
+// Copyright (c) 2020 The Chromium Embedded Framework Authors. All rights
+// reserved. Use of this source code is governed by a BSD-style license that
+// can be found in the LICENSE file.
+//
+// ---------------------------------------------------------------------------
+//
+// This file was generated by the CEF translator tool. If making changes by
+// hand only do so within the body of existing method and function
+// implementations. See the translator.README.txt file in the tools directory
+// for more information.
+//
+// $hash=d48f93f3817dab7daf0e30a6fa94b1a173356383$
+//
+
+#ifndef CEF_LIBCEF_DLL_CPPTOC_DEV_TOOLS_MESSAGE_OBSERVER_CPPTOC_H_
+#define CEF_LIBCEF_DLL_CPPTOC_DEV_TOOLS_MESSAGE_OBSERVER_CPPTOC_H_
+#pragma once
+
+#if !defined(WRAPPING_CEF_SHARED)
+#error This file can be included wrapper-side only
+#endif
+
+#include "include/capi/cef_browser_capi.h"
+#include "include/capi/cef_devtools_message_observer_capi.h"
+#include "include/cef_browser.h"
+#include "include/cef_devtools_message_observer.h"
+#include "libcef_dll/cpptoc/cpptoc_ref_counted.h"
+
+// Wrap a C++ class with a C structure.
+// This class may be instantiated and accessed wrapper-side only.
+class CefDevToolsMessageObserverCppToC
+    : public CefCppToCRefCounted<CefDevToolsMessageObserverCppToC,
+                                 CefDevToolsMessageObserver,
+                                 cef_dev_tools_message_observer_t> {
+ public:
+  CefDevToolsMessageObserverCppToC();
+  virtual ~CefDevToolsMessageObserverCppToC();
+};
+
+#endif  // CEF_LIBCEF_DLL_CPPTOC_DEV_TOOLS_MESSAGE_OBSERVER_CPPTOC_H_

libcef_dll/cpptoc/request_handler_cpptoc.cc

@@ -9,7 +9,7 @@
 // implementations. See the translator.README.txt file in the tools directory
 // for more information.
 //
-// $hash=68840d18a25efe4d749e480225d7ac3caacd4723$
+// $hash=716501855da0203723eb18bfb9e518c7b155f110$
 //
 
 #include "libcef_dll/cpptoc/request_handler_cpptoc.h"
@@ -396,6 +396,26 @@ void CEF_CALLBACK request_handler_on_render_process_terminated(
       CefBrowserCToCpp::Wrap(browser), status);
 }
 
+void CEF_CALLBACK request_handler_on_document_available_in_main_frame(
+    struct _cef_request_handler_t* self,
+    cef_browser_t* browser) {
+  shutdown_checker::AssertNotShutdown();
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  DCHECK(self);
+  if (!self)
+    return;
+  // Verify param: browser; type: refptr_diff
+  DCHECK(browser);
+  if (!browser)
+    return;
+
+  // Execute
+  CefRequestHandlerCppToC::Get(self)->OnDocumentAvailableInMainFrame(
+      CefBrowserCToCpp::Wrap(browser));
+}
+
 }  // namespace
 
 // CONSTRUCTOR - Do not edit by hand.
@@ -414,6 +434,8 @@ CefRequestHandlerCppToC::CefRequestHandlerCppToC() {
   GetStruct()->on_render_view_ready = request_handler_on_render_view_ready;
   GetStruct()->on_render_process_terminated =
       request_handler_on_render_process_terminated;
+  GetStruct()->on_document_available_in_main_frame =
+      request_handler_on_document_available_in_main_frame;
 }
 
 // DESTRUCTOR - Do not edit by hand.

libcef_dll/ctocpp/browser_host_ctocpp.cc

@@ -9,11 +9,12 @@
 // implementations. See the translator.README.txt file in the tools directory
 // for more information.
 //
-// $hash=9073823898d373a435ccdc56f2914aad91cbba1e$
+// $hash=a362e11e85ce68488bbb0f5232b01f53cffeec1d$
 //
 
 #include "libcef_dll/ctocpp/browser_host_ctocpp.h"
 #include "libcef_dll/cpptoc/client_cpptoc.h"
+#include "libcef_dll/cpptoc/dev_tools_message_observer_cpptoc.h"
 #include "libcef_dll/cpptoc/download_image_callback_cpptoc.h"
 #include "libcef_dll/cpptoc/navigation_entry_visitor_cpptoc.h"
 #include "libcef_dll/cpptoc/pdf_print_callback_cpptoc.h"
@@ -23,6 +24,7 @@
 #include "libcef_dll/ctocpp/drag_data_ctocpp.h"
 #include "libcef_dll/ctocpp/extension_ctocpp.h"
 #include "libcef_dll/ctocpp/navigation_entry_ctocpp.h"
+#include "libcef_dll/ctocpp/registration_ctocpp.h"
 #include "libcef_dll/ctocpp/request_context_ctocpp.h"
 #include "libcef_dll/shutdown_checker.h"
 #include "libcef_dll/transfer_util.h"
@@ -468,6 +470,81 @@ NO_SANITIZE("cfi-icall") bool CefBrowserHostCToCpp::HasDevTools() {
   return _retval ? true : false;
 }
 
+NO_SANITIZE("cfi-icall")
+bool CefBrowserHostCToCpp::SendDevToolsMessage(const void* message,
+                                               size_t message_size) {
+  shutdown_checker::AssertNotShutdown();
+
+  cef_browser_host_t* _struct = GetStruct();
+  if (CEF_MEMBER_MISSING(_struct, send_dev_tools_message))
+    return false;
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  // Verify param: message; type: simple_byaddr
+  DCHECK(message);
+  if (!message)
+    return false;
+
+  // Execute
+  int _retval = _struct->send_dev_tools_message(_struct, message, message_size);
+
+  // Return type: bool
+  return _retval ? true : false;
+}
+
+NO_SANITIZE("cfi-icall")
+int CefBrowserHostCToCpp::ExecuteDevToolsMethod(
+    int message_id,
+    const CefString& method,
+    CefRefPtr<CefDictionaryValue> params) {
+  shutdown_checker::AssertNotShutdown();
+
+  cef_browser_host_t* _struct = GetStruct();
+  if (CEF_MEMBER_MISSING(_struct, execute_dev_tools_method))
+    return 0;
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  // Verify param: method; type: string_byref_const
+  DCHECK(!method.empty());
+  if (method.empty())
+    return 0;
+  // Unverified params: params
+
+  // Execute
+  int _retval = _struct->execute_dev_tools_method(
+      _struct, message_id, method.GetStruct(),
+      CefDictionaryValueCToCpp::Unwrap(params));
+
+  // Return type: simple
+  return _retval;
+}
+
+NO_SANITIZE("cfi-icall")
+CefRefPtr<CefRegistration> CefBrowserHostCToCpp::AddDevToolsMessageObserver(
+    CefRefPtr<CefDevToolsMessageObserver> observer) {
+  shutdown_checker::AssertNotShutdown();
+
+  cef_browser_host_t* _struct = GetStruct();
+  if (CEF_MEMBER_MISSING(_struct, add_dev_tools_message_observer))
+    return nullptr;
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  // Verify param: observer; type: refptr_diff
+  DCHECK(observer.get());
+  if (!observer.get())
+    return nullptr;
+
+  // Execute
+  cef_registration_t* _retval = _struct->add_dev_tools_message_observer(
+      _struct, CefDevToolsMessageObserverCppToC::Wrap(observer));
+
+  // Return type: refptr_same
+  return CefRegistrationCToCpp::Wrap(_retval);
+}
+
 NO_SANITIZE("cfi-icall")
 void CefBrowserHostCToCpp::GetNavigationEntries(
     CefRefPtr<CefNavigationEntryVisitor> visitor,

libcef_dll/ctocpp/browser_host_ctocpp.h

@@ -9,7 +9,7 @@
 // implementations. See the translator.README.txt file in the tools directory
 // for more information.
 //
-// $hash=a9c5f9224663a0c2f2a29c35c2dea3f47973b82f$
+// $hash=c9abd1293472afbac964aac4cd7dd4cac9dd8e58$
 //
 
 #ifndef CEF_LIBCEF_DLL_CTOCPP_BROWSER_HOST_CTOCPP_H_
@@ -76,6 +76,12 @@ class CefBrowserHostCToCpp : public CefCToCppRefCounted<CefBrowserHostCToCpp,
                     const CefPoint& inspect_element_at) OVERRIDE;
   void CloseDevTools() OVERRIDE;
   bool HasDevTools() OVERRIDE;
+  bool SendDevToolsMessage(const void* message, size_t message_size) OVERRIDE;
+  int ExecuteDevToolsMethod(int message_id,
+                            const CefString& method,
+                            CefRefPtr<CefDictionaryValue> params) OVERRIDE;
+  CefRefPtr<CefRegistration> AddDevToolsMessageObserver(
+      CefRefPtr<CefDevToolsMessageObserver> observer) OVERRIDE;
   void GetNavigationEntries(CefRefPtr<CefNavigationEntryVisitor> visitor,
                             bool current_only) OVERRIDE;
   void SetMouseCursorChangeDisabled(bool disabled) OVERRIDE;

libcef_dll/ctocpp/dev_tools_message_observer_ctocpp.cc

@@ -0,0 +1,174 @@
+// Copyright (c) 2020 The Chromium Embedded Framework Authors. All rights
+// reserved. Use of this source code is governed by a BSD-style license that
+// can be found in the LICENSE file.
+//
+// ---------------------------------------------------------------------------
+//
+// This file was generated by the CEF translator tool. If making changes by
+// hand only do so within the body of existing method and function
+// implementations. See the translator.README.txt file in the tools directory
+// for more information.
+//
+// $hash=e8d1eaf4b8cdfd79a260de33fb3be05a2948c81e$
+//
+
+#include "libcef_dll/ctocpp/dev_tools_message_observer_ctocpp.h"
+#include "libcef_dll/cpptoc/browser_cpptoc.h"
+#include "libcef_dll/shutdown_checker.h"
+
+// VIRTUAL METHODS - Body may be edited by hand.
+
+NO_SANITIZE("cfi-icall")
+bool CefDevToolsMessageObserverCToCpp::OnDevToolsMessage(
+    CefRefPtr<CefBrowser> browser,
+    const void* message,
+    size_t message_size) {
+  shutdown_checker::AssertNotShutdown();
+
+  cef_dev_tools_message_observer_t* _struct = GetStruct();
+  if (CEF_MEMBER_MISSING(_struct, on_dev_tools_message))
+    return false;
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  // Verify param: browser; type: refptr_diff
+  DCHECK(browser.get());
+  if (!browser.get())
+    return false;
+  // Verify param: message; type: simple_byaddr
+  DCHECK(message);
+  if (!message)
+    return false;
+
+  // Execute
+  int _retval = _struct->on_dev_tools_message(
+      _struct, CefBrowserCppToC::Wrap(browser), message, message_size);
+
+  // Return type: bool
+  return _retval ? true : false;
+}
+
+NO_SANITIZE("cfi-icall")
+void CefDevToolsMessageObserverCToCpp::OnDevToolsMethodResult(
+    CefRefPtr<CefBrowser> browser,
+    int message_id,
+    bool success,
+    const void* result,
+    size_t result_size) {
+  shutdown_checker::AssertNotShutdown();
+
+  cef_dev_tools_message_observer_t* _struct = GetStruct();
+  if (CEF_MEMBER_MISSING(_struct, on_dev_tools_method_result))
+    return;
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  // Verify param: browser; type: refptr_diff
+  DCHECK(browser.get());
+  if (!browser.get())
+    return;
+  // Unverified params: result
+
+  // Execute
+  _struct->on_dev_tools_method_result(_struct, CefBrowserCppToC::Wrap(browser),
+                                      message_id, success, result, result_size);
+}
+
+NO_SANITIZE("cfi-icall")
+void CefDevToolsMessageObserverCToCpp::OnDevToolsEvent(
+    CefRefPtr<CefBrowser> browser,
+    const CefString& method,
+    const void* params,
+    size_t params_size) {
+  shutdown_checker::AssertNotShutdown();
+
+  cef_dev_tools_message_observer_t* _struct = GetStruct();
+  if (CEF_MEMBER_MISSING(_struct, on_dev_tools_event))
+    return;
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  // Verify param: browser; type: refptr_diff
+  DCHECK(browser.get());
+  if (!browser.get())
+    return;
+  // Verify param: method; type: string_byref_const
+  DCHECK(!method.empty());
+  if (method.empty())
+    return;
+  // Unverified params: params
+
+  // Execute
+  _struct->on_dev_tools_event(_struct, CefBrowserCppToC::Wrap(browser),
+                              method.GetStruct(), params, params_size);
+}
+
+NO_SANITIZE("cfi-icall")
+void CefDevToolsMessageObserverCToCpp::OnDevToolsAgentAttached(
+    CefRefPtr<CefBrowser> browser) {
+  shutdown_checker::AssertNotShutdown();
+
+  cef_dev_tools_message_observer_t* _struct = GetStruct();
+  if (CEF_MEMBER_MISSING(_struct, on_dev_tools_agent_attached))
+    return;
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  // Verify param: browser; type: refptr_diff
+  DCHECK(browser.get());
+  if (!browser.get())
+    return;
+
+  // Execute
+  _struct->on_dev_tools_agent_attached(_struct,
+                                       CefBrowserCppToC::Wrap(browser));
+}
+
+NO_SANITIZE("cfi-icall")
+void CefDevToolsMessageObserverCToCpp::OnDevToolsAgentDetached(
+    CefRefPtr<CefBrowser> browser) {
+  shutdown_checker::AssertNotShutdown();
+
+  cef_dev_tools_message_observer_t* _struct = GetStruct();
+  if (CEF_MEMBER_MISSING(_struct, on_dev_tools_agent_detached))
+    return;
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  // Verify param: browser; type: refptr_diff
+  DCHECK(browser.get());
+  if (!browser.get())
+    return;
+
+  // Execute
+  _struct->on_dev_tools_agent_detached(_struct,
+                                       CefBrowserCppToC::Wrap(browser));
+}
+
+// CONSTRUCTOR - Do not edit by hand.
+
+CefDevToolsMessageObserverCToCpp::CefDevToolsMessageObserverCToCpp() {}
+
+// DESTRUCTOR - Do not edit by hand.
+
+CefDevToolsMessageObserverCToCpp::~CefDevToolsMessageObserverCToCpp() {
+  shutdown_checker::AssertNotShutdown();
+}
+
+template <>
+cef_dev_tools_message_observer_t* CefCToCppRefCounted<
+    CefDevToolsMessageObserverCToCpp,
+    CefDevToolsMessageObserver,
+    cef_dev_tools_message_observer_t>::UnwrapDerived(CefWrapperType type,
+                                                     CefDevToolsMessageObserver*
+                                                         c) {
+  NOTREACHED() << "Unexpected class type: " << type;
+  return nullptr;
+}
+
+template <>
+CefWrapperType
+    CefCToCppRefCounted<CefDevToolsMessageObserverCToCpp,
+                        CefDevToolsMessageObserver,
+                        cef_dev_tools_message_observer_t>::kWrapperType =
+        WT_DEV_TOOLS_MESSAGE_OBSERVER;

libcef_dll/ctocpp/dev_tools_message_observer_ctocpp.h

@@ -0,0 +1,56 @@
+// Copyright (c) 2020 The Chromium Embedded Framework Authors. All rights
+// reserved. Use of this source code is governed by a BSD-style license that
+// can be found in the LICENSE file.
+//
+// ---------------------------------------------------------------------------
+//
+// This file was generated by the CEF translator tool. If making changes by
+// hand only do so within the body of existing method and function
+// implementations. See the translator.README.txt file in the tools directory
+// for more information.
+//
+// $hash=26b1ef9d351b0ce4a7ca0d61c53a8374ba21168b$
+//
+
+#ifndef CEF_LIBCEF_DLL_CTOCPP_DEV_TOOLS_MESSAGE_OBSERVER_CTOCPP_H_
+#define CEF_LIBCEF_DLL_CTOCPP_DEV_TOOLS_MESSAGE_OBSERVER_CTOCPP_H_
+#pragma once
+
+#if !defined(BUILDING_CEF_SHARED)
+#error This file can be included DLL-side only
+#endif
+
+#include "include/capi/cef_browser_capi.h"
+#include "include/capi/cef_devtools_message_observer_capi.h"
+#include "include/cef_browser.h"
+#include "include/cef_devtools_message_observer.h"
+#include "libcef_dll/ctocpp/ctocpp_ref_counted.h"
+
+// Wrap a C structure with a C++ class.
+// This class may be instantiated and accessed DLL-side only.
+class CefDevToolsMessageObserverCToCpp
+    : public CefCToCppRefCounted<CefDevToolsMessageObserverCToCpp,
+                                 CefDevToolsMessageObserver,
+                                 cef_dev_tools_message_observer_t> {
+ public:
+  CefDevToolsMessageObserverCToCpp();
+  virtual ~CefDevToolsMessageObserverCToCpp();
+
+  // CefDevToolsMessageObserver methods.
+  bool OnDevToolsMessage(CefRefPtr<CefBrowser> browser,
+                         const void* message,
+                         size_t message_size) override;
+  void OnDevToolsMethodResult(CefRefPtr<CefBrowser> browser,
+                              int message_id,
+                              bool success,
+                              const void* result,
+                              size_t result_size) override;
+  void OnDevToolsEvent(CefRefPtr<CefBrowser> browser,
+                       const CefString& method,
+                       const void* params,
+                       size_t params_size) override;
+  void OnDevToolsAgentAttached(CefRefPtr<CefBrowser> browser) override;
+  void OnDevToolsAgentDetached(CefRefPtr<CefBrowser> browser) override;
+};
+
+#endif  // CEF_LIBCEF_DLL_CTOCPP_DEV_TOOLS_MESSAGE_OBSERVER_CTOCPP_H_

libcef_dll/ctocpp/request_handler_ctocpp.cc

@@ -9,7 +9,7 @@
 // implementations. See the translator.README.txt file in the tools directory
 // for more information.
 //
-// $hash=72e6ec9a5095a99eaa78ff867ca429f8cd28b101$
+// $hash=fdcb73f79369fe74f65f75d54f08aaec0f0e4dbf$
 //
 
 #include "libcef_dll/ctocpp/request_handler_ctocpp.h"
@@ -394,6 +394,27 @@ void CefRequestHandlerCToCpp::OnRenderProcessTerminated(
       _struct, CefBrowserCppToC::Wrap(browser), status);
 }
 
+NO_SANITIZE("cfi-icall")
+void CefRequestHandlerCToCpp::OnDocumentAvailableInMainFrame(
+    CefRefPtr<CefBrowser> browser) {
+  shutdown_checker::AssertNotShutdown();
+
+  cef_request_handler_t* _struct = GetStruct();
+  if (CEF_MEMBER_MISSING(_struct, on_document_available_in_main_frame))
+    return;
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  // Verify param: browser; type: refptr_diff
+  DCHECK(browser.get());
+  if (!browser.get())
+    return;
+
+  // Execute
+  _struct->on_document_available_in_main_frame(_struct,
+                                               CefBrowserCppToC::Wrap(browser));
+}
+
 // CONSTRUCTOR - Do not edit by hand.
 
 CefRequestHandlerCToCpp::CefRequestHandlerCToCpp() {}

libcef_dll/ctocpp/request_handler_ctocpp.h

@@ -9,7 +9,7 @@
 // implementations. See the translator.README.txt file in the tools directory
 // for more information.
 //
-// $hash=0d67e24bf6d8079bcdfd8b36ba48543a05a9d2fd$
+// $hash=be2bb80e8816f0eaad34382f05e2bec59dfe7fa7$
 //
 
 #ifndef CEF_LIBCEF_DLL_CTOCPP_REQUEST_HANDLER_CTOCPP_H_
@@ -82,6 +82,7 @@ class CefRequestHandlerCToCpp
   void OnRenderViewReady(CefRefPtr<CefBrowser> browser) override;
   void OnRenderProcessTerminated(CefRefPtr<CefBrowser> browser,
                                  TerminationStatus status) override;
+  void OnDocumentAvailableInMainFrame(CefRefPtr<CefBrowser> browser) override;
 };
 
 #endif  // CEF_LIBCEF_DLL_CTOCPP_REQUEST_HANDLER_CTOCPP_H_

libcef_dll/libcef_dll.cc

@@ -9,7 +9,7 @@
 // implementations. See the translator.README.txt file in the tools directory
 // for more information.
 //
-// $hash=fbf992432bd4ff88bed34f803047f70b5b3400f7$
+// $hash=c42cd0225d8e4286df471fcc622f9bbf9ed977d3$
 //
 
 #include "include/capi/cef_app_capi.h"
@@ -589,6 +589,24 @@ CEF_EXPORT struct _cef_value_t* cef_parse_json(
   return CefValueCppToC::Wrap(_retval);
 }
 
+CEF_EXPORT struct _cef_value_t* cef_parse_json_buffer(
+    const void* json,
+    size_t json_size,
+    cef_json_parser_options_t options) {
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  // Verify param: json; type: simple_byaddr
+  DCHECK(json);
+  if (!json)
+    return NULL;
+
+  // Execute
+  CefRefPtr<CefValue> _retval = CefParseJSON(json, json_size, options);
+
+  // Return type: refptr_same
+  return CefValueCppToC::Wrap(_retval);
+}
+
 CEF_EXPORT struct _cef_value_t* cef_parse_jsonand_return_error(
     const cef_string_t* json_string,
     cef_json_parser_options_t options,

libcef_dll/wrapper/libcef_dll_dylib.cc

@@ -9,7 +9,7 @@
 // implementations. See the translator.README.txt file in the tools directory
 // for more information.
 //
-// $hash=bf82965f02cafae5a1afc80ab0c976436be9712e$
+// $hash=66b734973339eb27399083e978844f7d5a6a6c44$
 //
 
 #include <dlfcn.h>
@@ -139,6 +139,8 @@ typedef cef_string_userfree_t (*cef_uridecode_ptr)(const cef_string_t*,
                                                    cef_uri_unescape_rule_t);
 typedef struct _cef_value_t* (*cef_parse_json_ptr)(const cef_string_t*,
                                                    cef_json_parser_options_t);
+typedef struct _cef_value_t* (
+    *cef_parse_json_buffer_ptr)(const void*, size_t, cef_json_parser_options_t);
 typedef struct _cef_value_t* (*cef_parse_jsonand_return_error_ptr)(
     const cef_string_t*,
     cef_json_parser_options_t,
@@ -547,6 +549,7 @@ struct libcef_pointers {
   cef_uriencode_ptr cef_uriencode;
   cef_uridecode_ptr cef_uridecode;
   cef_parse_json_ptr cef_parse_json;
+  cef_parse_json_buffer_ptr cef_parse_json_buffer;
   cef_parse_jsonand_return_error_ptr cef_parse_jsonand_return_error;
   cef_write_json_ptr cef_write_json;
   cef_get_path_ptr cef_get_path;
@@ -763,6 +766,7 @@ int libcef_init_pointers(const char* path) {
   INIT_ENTRY(cef_uriencode);
   INIT_ENTRY(cef_uridecode);
   INIT_ENTRY(cef_parse_json);
+  INIT_ENTRY(cef_parse_json_buffer);
   INIT_ENTRY(cef_parse_jsonand_return_error);
   INIT_ENTRY(cef_write_json);
   INIT_ENTRY(cef_get_path);
@@ -1134,6 +1138,13 @@ struct _cef_value_t* cef_parse_json(const cef_string_t* json_string,
   return g_libcef_pointers.cef_parse_json(json_string, options);
 }
 
+NO_SANITIZE("cfi-icall")
+struct _cef_value_t* cef_parse_json_buffer(const void* json,
+                                           size_t json_size,
+                                           cef_json_parser_options_t options) {
+  return g_libcef_pointers.cef_parse_json_buffer(json, json_size, options);
+}
+
 NO_SANITIZE("cfi-icall")
 struct _cef_value_t* cef_parse_jsonand_return_error(
     const cef_string_t* json_string,

libcef_dll/wrapper/libcef_dll_wrapper.cc

@@ -9,7 +9,7 @@
 // implementations. See the translator.README.txt file in the tools directory
 // for more information.
 //
-// $hash=c565ea9030eeed15f24fe420b828453a23dbc6ba$
+// $hash=7db8dbe24a2510d9ae0649f1569909711017c064$
 //
 
 #include "include/capi/cef_app_capi.h"
@@ -557,6 +557,24 @@ CEF_GLOBAL CefRefPtr<CefValue> CefParseJSON(const CefString& json_string,
   return CefValueCToCpp::Wrap(_retval);
 }
 
+NO_SANITIZE("cfi-icall")
+CEF_GLOBAL CefRefPtr<CefValue> CefParseJSON(const void* json,
+                                            size_t json_size,
+                                            cef_json_parser_options_t options) {
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  // Verify param: json; type: simple_byaddr
+  DCHECK(json);
+  if (!json)
+    return nullptr;
+
+  // Execute
+  cef_value_t* _retval = cef_parse_json_buffer(json, json_size, options);
+
+  // Return type: refptr_same
+  return CefValueCToCpp::Wrap(_retval);
+}
+
 NO_SANITIZE("cfi-icall")
 CEF_GLOBAL CefRefPtr<CefValue> CefParseJSONAndReturnError(
     const CefString& json_string,

libcef_dll/wrapper_types.h

@@ -9,7 +9,7 @@
 // implementations. See the translator.README.txt file in the tools directory
 // for more information.
 //
-// $hash=9bfe176dfac4770800e95e2bbc0fafffbf0aeeaf$
+// $hash=20268db646dcf8aa6d54b2342dbc70a6e624e202$
 //
 
 #ifndef CEF_LIBCEF_DLL_WRAPPER_TYPES_H_
@@ -46,6 +46,7 @@ enum CefWrapperType {
   WT_DOMNODE,
   WT_DOMVISITOR,
   WT_DELETE_COOKIES_CALLBACK,
+  WT_DEV_TOOLS_MESSAGE_OBSERVER,
   WT_DIALOG_HANDLER,
   WT_DICTIONARY_VALUE,
   WT_DISPLAY,

tests/cefclient/browser/client_handler.cc

@@ -41,6 +41,7 @@ enum client_menu_ids {
   CLIENT_ID_INSPECT_ELEMENT,
   CLIENT_ID_SHOW_SSL_INFO,
   CLIENT_ID_CURSOR_CHANGE_DISABLED,
+  CLIENT_ID_OFFLINE,
   CLIENT_ID_TESTMENU_SUBMENU,
   CLIENT_ID_TESTMENU_CHECKITEM,
   CLIENT_ID_TESTMENU_RADIOITEM1,
@@ -268,6 +269,7 @@ ClientHandler::ClientHandler(Delegate* delegate,
       CefCommandLine::GetGlobalCommandLine();
   mouse_cursor_change_disabled_ =
       command_line->HasSwitch(switches::kMouseCursorChangeDisabled);
+  offline_ = command_line->HasSwitch(switches::kOffline);
 }
 
 void ClientHandler::DetachDelegate() {
@@ -334,6 +336,11 @@ void ClientHandler::OnBeforeContextMenu(CefRefPtr<CefBrowser> browser,
     if (browser->GetHost()->IsMouseCursorChangeDisabled())
       model->SetChecked(CLIENT_ID_CURSOR_CHANGE_DISABLED, true);
 
+    model->AddSeparator();
+    model->AddItem(CLIENT_ID_OFFLINE, "Offline mode");
+    if (offline_)
+      model->SetChecked(CLIENT_ID_OFFLINE, true);
+
     // Test context menu features.
     BuildTestMenu(model);
   }
@@ -366,6 +373,10 @@ bool ClientHandler::OnContextMenuCommand(CefRefPtr<CefBrowser> browser,
       browser->GetHost()->SetMouseCursorChangeDisabled(
           !browser->GetHost()->IsMouseCursorChangeDisabled());
       return true;
+    case CLIENT_ID_OFFLINE:
+      offline_ = !offline_;
+      SetOfflineState(browser, offline_);
+      return true;
     default:  // Allow default handling, if any.
       return ExecuteTestMenu(command_id);
   }
@@ -588,6 +599,10 @@ void ClientHandler::OnAfterCreated(CefRefPtr<CefBrowser> browser) {
   if (mouse_cursor_change_disabled_)
     browser->GetHost()->SetMouseCursorChangeDisabled(true);
 
+  // Set offline mode if requested via the command-line flag.
+  if (offline_)
+    SetOfflineState(browser, true);
+
   if (browser->GetHost()->GetExtension()) {
     // Browsers hosting extension apps should auto-resize.
     browser->GetHost()->SetAutoResizeEnabled(true, CefSize(20, 20),
@@ -843,6 +858,16 @@ void ClientHandler::OnRenderProcessTerminated(CefRefPtr<CefBrowser> browser,
   frame->LoadURL(startup_url_);
 }
 
+void ClientHandler::OnDocumentAvailableInMainFrame(
+    CefRefPtr<CefBrowser> browser) {
+  CEF_REQUIRE_UI_THREAD();
+
+  // Restore offline mode after main frame navigation. Otherwise, offline state
+  // (e.g. `navigator.onLine`) might be wrong in the renderer process.
+  if (offline_)
+    SetOfflineState(browser, true);
+}
+
 cef_return_value_t ClientHandler::OnBeforeResourceLoad(
     CefRefPtr<CefBrowser> browser,
     CefRefPtr<CefFrame> frame,
@@ -1178,4 +1203,16 @@ bool ClientHandler::ExecuteTestMenu(int command_id) {
   return false;
 }
 
+void ClientHandler::SetOfflineState(CefRefPtr<CefBrowser> browser,
+                                    bool offline) {
+  // See DevTools protocol docs for message format specification.
+  CefRefPtr<CefDictionaryValue> params = CefDictionaryValue::Create();
+  params->SetBool("offline", offline);
+  params->SetDouble("latency", 0);
+  params->SetDouble("downloadThroughput", 0);
+  params->SetDouble("uploadThroughput", 0);
+  browser->GetHost()->ExecuteDevToolsMethod(
+      /*message_id=*/0, "Network.emulateNetworkConditions", params);
+}
+
 }  // namespace client

tests/cefclient/browser/client_handler.h

@@ -256,6 +256,7 @@ class ClientHandler : public CefClient,
       CefRefPtr<CefSelectClientCertificateCallback> callback) OVERRIDE;
   void OnRenderProcessTerminated(CefRefPtr<CefBrowser> browser,
                                  TerminationStatus status) OVERRIDE;
+  void OnDocumentAvailableInMainFrame(CefRefPtr<CefBrowser> browser) OVERRIDE;
 
   // CefResourceRequestHandler methods
   cef_return_value_t OnBeforeResourceLoad(
@@ -344,6 +345,8 @@ class ClientHandler : public CefClient,
   void BuildTestMenu(CefRefPtr<CefMenuModel> model);
   bool ExecuteTestMenu(int command_id);
 
+  void SetOfflineState(CefRefPtr<CefBrowser> browser, bool offline);
+
   // THREAD SAFE MEMBERS
   // The following members may be accessed from any thread.
 
@@ -356,6 +359,9 @@ class ClientHandler : public CefClient,
   // True if mouse cursor change is disabled.
   bool mouse_cursor_change_disabled_;
 
+  // True if the browser is currently offline.
+  bool offline_;
+
   // True if Favicon images should be downloaded.
   bool download_favicon_images_;
 

tests/ceftests/devtools_message_unittest.cc

@@ -0,0 +1,375 @@
+// Copyright (c) 2020 The Chromium Embedded Framework Authors. All rights
+// reserved. Use of this source code is governed by a BSD-style license that
+// can be found in the LICENSE file.
+
+#include <algorithm>
+#include <sstream>
+
+#include "include/base/cef_bind.h"
+#include "include/cef_callback.h"
+#include "include/cef_devtools_message_observer.h"
+#include "include/cef_parser.h"
+#include "include/wrapper/cef_closure_task.h"
+
+#include "tests/ceftests/test_handler.h"
+#include "tests/gtest/include/gtest/gtest.h"
+
+namespace {
+
+const char kTestUrl1[] = "http://tests/DevToolsMessage1";
+const char kTestUrl2[] = "http://tests/DevToolsMessage2";
+
+class DevToolsMessageTestHandler : public TestHandler {
+ public:
+  DevToolsMessageTestHandler() {}
+
+  void RunTest() override {
+    // Add HTML resources.
+    AddResource(kTestUrl1, "<html><body>Test1</body></html>", "text/html");
+    AddResource(kTestUrl2, "<html><body>Test2</body></html>", "text/html");
+
+    // Create the browser.
+    CreateBrowser(kTestUrl1);
+
+    // Time out the test after a reasonable period of time.
+    SetTestTimeout();
+  }
+
+  void OnAfterCreated(CefRefPtr<CefBrowser> browser) override {
+    TestHandler::OnAfterCreated(browser);
+
+    // STEP 1: Add the DevTools observer. Wait for the 1st load.
+    registration_ = browser->GetHost()->AddDevToolsMessageObserver(
+        new TestMessageObserver(this));
+    EXPECT_TRUE(registration_);
+  }
+
+  void OnLoadingStateChange(CefRefPtr<CefBrowser> browser,
+                            bool isLoading,
+                            bool canGoBack,
+                            bool canGoForward) override {
+    if (!isLoading) {
+      load_ct_++;
+      if (load_ct_ == 1) {
+        // STEP 2: 1st load has completed. Now enable page domain notifications
+        // and wait for the method result.
+        ExecuteMethod("Page.enable", "",
+                      base::Bind(&DevToolsMessageTestHandler::Navigate, this));
+      } else if (load_ct_ == 2) {
+        MaybeDestroyTest();
+      }
+    }
+  }
+
+  void DestroyTest() override {
+    // STEP 7: Remove the DevTools observer. This should result in the observer
+    // object being destroyed.
+    EXPECT_TRUE(registration_);
+    registration_ = nullptr;
+    EXPECT_TRUE(observer_destroyed_);
+
+    // Each send message variant should be called at least a single time.
+    EXPECT_GE(method_send_ct_, 1);
+    EXPECT_GE(method_execute_ct_, 1);
+
+    // All sent messages should receive a result callback.
+    EXPECT_EQ(expected_method_ct_, method_send_ct_ + method_execute_ct_);
+    EXPECT_EQ(expected_method_ct_, result_ct_);
+    EXPECT_EQ(expected_method_ct_, last_result_id_);
+
+    // Every received message should parse successfully to a result or event
+    // callback.
+    EXPECT_EQ(message_ct_, result_ct_ + event_ct_);
+
+    // Should receive 1 or more events (probably just 1, but who knows?).
+    EXPECT_GE(event_ct_, 1);
+
+    // OnLoadingStateChange(isLoading=false) should be called twice.
+    EXPECT_EQ(expected_load_ct_, load_ct_);
+
+    // Should get callbacks for agent attached but not detached.
+    EXPECT_EQ(1, attached_ct_);
+    EXPECT_EQ(0, detached_ct_);
+
+    TestHandler::DestroyTest();
+  }
+
+ private:
+  struct MethodResult {
+    int message_id;
+    bool success;
+    std::string result;
+  };
+
+  struct Event {
+    std::string method;
+    std::string params;
+  };
+
+  class TestMessageObserver : public CefDevToolsMessageObserver {
+   public:
+    explicit TestMessageObserver(DevToolsMessageTestHandler* handler)
+        : handler_(handler) {}
+
+    virtual ~TestMessageObserver() { handler_->observer_destroyed_.yes(); }
+
+    bool OnDevToolsMessage(CefRefPtr<CefBrowser> browser,
+                           const void* message,
+                           size_t message_size) override {
+      EXPECT_TRUE(browser.get());
+      EXPECT_EQ(handler_->GetBrowserId(), browser->GetIdentifier());
+      handler_->message_ct_++;
+      return false;
+    }
+
+    void OnDevToolsMethodResult(CefRefPtr<CefBrowser> browser,
+                                int message_id,
+                                bool success,
+                                const void* result,
+                                size_t result_size) override {
+      EXPECT_TRUE(browser.get());
+      EXPECT_EQ(handler_->GetBrowserId(), browser->GetIdentifier());
+      handler_->result_ct_++;
+
+      MethodResult mr;
+      mr.message_id = message_id;
+      mr.success = success;
+      if (result) {
+        // Intentionally truncating at small size.
+        mr.result = std::string(static_cast<const char*>(result),
+                                std::min(static_cast<int>(result_size), 80));
+      }
+      handler_->OnMethodResult(mr);
+    }
+
+    void OnDevToolsEvent(CefRefPtr<CefBrowser> browser,
+                         const CefString& method,
+                         const void* params,
+                         size_t params_size) override {
+      EXPECT_TRUE(browser.get());
+      EXPECT_EQ(handler_->GetBrowserId(), browser->GetIdentifier());
+      handler_->event_ct_++;
+
+      Event ev;
+      ev.method = method;
+      if (params) {
+        // Intentionally truncating at small size.
+        ev.params = std::string(static_cast<const char*>(params),
+                                std::min(static_cast<int>(params_size), 80));
+      }
+      handler_->OnEvent(ev);
+    }
+
+    void OnDevToolsAgentAttached(CefRefPtr<CefBrowser> browser) override {
+      EXPECT_TRUE(browser.get());
+      EXPECT_EQ(handler_->GetBrowserId(), browser->GetIdentifier());
+      handler_->attached_ct_++;
+    }
+
+    void OnDevToolsAgentDetached(CefRefPtr<CefBrowser> browser) override {
+      EXPECT_TRUE(browser.get());
+      EXPECT_EQ(handler_->GetBrowserId(), browser->GetIdentifier());
+      handler_->detached_ct_++;
+    }
+
+   private:
+    DevToolsMessageTestHandler* handler_;
+
+    IMPLEMENT_REFCOUNTING(TestMessageObserver);
+    DISALLOW_COPY_AND_ASSIGN(TestMessageObserver);
+  };
+
+  // Execute a DevTools method. Expected results will be verified in
+  // OnMethodResult, and |next_step| will then be executed.
+  // |expected_result| can be a fragment that the result should start with.
+  void ExecuteMethod(const std::string& method,
+                     const std::string& params,
+                     const base::Closure& next_step,
+                     const std::string& expected_result = "{}",
+                     bool expected_success = true) {
+    CHECK(!method.empty());
+    CHECK(!next_step.is_null());
+
+    int message_id = next_message_id_++;
+
+    std::stringstream message;
+    message << "{\"id\":" << message_id << ",\"method\":\"" << method << "\"";
+    if (!params.empty()) {
+      message << ",\"params\":" << params;
+    }
+    message << "}";
+
+    // Set expected result state.
+    pending_message_ = message.str();
+    pending_result_next_ = next_step;
+    pending_result_ = {message_id, expected_success, expected_result};
+
+    if (message_id % 2 == 0) {
+      // Use the less structured method.
+      method_send_ct_++;
+      GetBrowser()->GetHost()->SendDevToolsMessage(pending_message_.data(),
+                                                   pending_message_.size());
+    } else {
+      // Use the more structured method.
+      method_execute_ct_++;
+      CefRefPtr<CefDictionaryValue> dict;
+      if (!params.empty()) {
+        CefRefPtr<CefValue> value =
+            CefParseJSON(params.data(), params.size(), JSON_PARSER_RFC);
+        EXPECT_TRUE(value && value->GetType() == VTYPE_DICTIONARY)
+            << "failed to parse: " << params;
+        if (value && value->GetType() == VTYPE_DICTIONARY) {
+          dict = value->GetDictionary();
+        }
+      }
+      GetBrowser()->GetHost()->ExecuteDevToolsMethod(message_id, method, dict);
+    }
+  }
+
+  // Every call to ExecuteMethod should result in a single call to this method
+  // with the same message_id.
+  void OnMethodResult(const MethodResult& result) {
+    EXPECT_EQ(pending_result_.message_id, result.message_id)
+        << "with message=" << pending_message_;
+    if (result.message_id != pending_result_.message_id)
+      return;
+
+    EXPECT_EQ(pending_result_.success, result.success)
+        << "with message=" << pending_message_;
+
+    EXPECT_TRUE(result.result.find(pending_result_.result) == 0)
+        << "with message=" << pending_message_
+        << "\nand actual result=" << result.result
+        << "\nand expected result=" << pending_result_.result;
+
+    last_result_id_ = result.message_id;
+
+    // Continue asynchronously to allow the callstack to unwind.
+    CefPostTask(TID_UI, pending_result_next_);
+
+    // Clear expected result state.
+    pending_message_.clear();
+    pending_result_next_.Reset();
+    pending_result_ = {};
+  }
+
+  void OnEvent(const Event& event) {
+    if (event.method != pending_event_.method)
+      return;
+
+    EXPECT_TRUE(event.params.find(pending_event_.params) == 0)
+        << "with method=" << event.method
+        << "\nand actual params=" << event.params
+        << "\nand expected params=" << pending_event_.params;
+
+    // Continue asynchronously to allow the callstack to unwind.
+    CefPostTask(TID_UI, pending_event_next_);
+
+    // Clear expected result state.
+    pending_event_ = {};
+    pending_event_next_.Reset();
+  }
+
+  void Navigate() {
+    pending_event_ = {"Page.frameNavigated", "{\"frame\":"};
+    pending_event_next_ =
+        base::Bind(&DevToolsMessageTestHandler::AfterNavigate, this);
+
+    std::stringstream params;
+    params << "{\"url\":\"" << kTestUrl2 << "\"}";
+
+    // STEP 3: Page domain notifications are enabled. Now start a new
+    // navigation (but do nothing on method result) and wait for the
+    // "Page.frameNavigated" event.
+    ExecuteMethod("Page.navigate", params.str(), base::Bind(base::DoNothing),
+                  /*expected_result=*/"{\"frameId\":");
+  }
+
+  void AfterNavigate() {
+    // STEP 4: Got the "Page.frameNavigated" event. Now disable page domain
+    // notifications.
+    ExecuteMethod(
+        "Page.disable", "",
+        base::Bind(&DevToolsMessageTestHandler::AfterPageDisabled, this));
+  }
+
+  void AfterPageDisabled() {
+    // STEP 5: Got the the "Page.disable" method result. Now call a non-existant
+    // method to verify an error result, and then destroy the test when done.
+    ExecuteMethod(
+        "Foo.doesNotExist", "",
+        base::Bind(&DevToolsMessageTestHandler::MaybeDestroyTest, this),
+        /*expected_result=*/
+        "{\"code\":-32601,\"message\":\"'Foo.doesNotExist' wasn't found\"}",
+        /*expected_success=*/false);
+  }
+
+  void MaybeDestroyTest() {
+    if (result_ct_ == expected_method_ct_ && load_ct_ == expected_load_ct_) {
+      // STEP 6: Got confirmation of all expected method results and load
+      // events. Now destroy the test.
+      DestroyTest();
+    }
+  }
+
+  // Total # of times we're planning to call ExecuteMethod.
+  const int expected_method_ct_ = 4;
+
+  // Total # of times we're expecting OnLoadingStateChange(isLoading=false) to
+  // be called.
+  const int expected_load_ct_ = 2;
+
+  // In ExecuteMethod:
+  //   Next message ID to use.
+  int next_message_id_ = 1;
+  //   Last message that was sent (used for debug messages only).
+  std::string pending_message_;
+  //   SendDevToolsMessage call count.
+  int method_send_ct_ = 0;
+  //   ExecuteDevToolsMethod call count.
+  int method_execute_ct_ = 0;
+
+  // Expect |pending_result_.message_id| in OnMethodResult.
+  // The result should start with the |pending_result_.result| fragment.
+  MethodResult pending_result_;
+  //   Tracks the last message ID received.
+  int last_result_id_ = -1;
+  //   When received, execute this callback.
+  base::Closure pending_result_next_;
+
+  // Wait for |pending_event_.method| in OnEvent.
+  // The params should start with the |pending_event_.params| fragment.
+  Event pending_event_;
+  //   When received, execute this callback.
+  base::Closure pending_event_next_;
+
+  CefRefPtr<CefRegistration> registration_;
+
+  // Observer callback count.
+  int message_ct_ = 0;
+  int result_ct_ = 0;
+  int event_ct_ = 0;
+  int attached_ct_ = 0;
+  int detached_ct_ = 0;
+
+  // OnLoadingStateChange(isLoading=false) count.
+  int load_ct_ = 0;
+
+  TrackCallback observer_destroyed_;
+
+  IMPLEMENT_REFCOUNTING(DevToolsMessageTestHandler);
+  DISALLOW_COPY_AND_ASSIGN(DevToolsMessageTestHandler);
+};
+
+}  // namespace
+
+// Test everything related to DevTools messages:
+// - CefDevToolsMessageObserver registration and life span.
+// - SendDevToolsMessage/ExecuteDevToolsMethod calls.
+// - CefDevToolsMessageObserver callbacks for method results and events.
+TEST(DevToolsMessageTest, Messages) {
+  CefRefPtr<DevToolsMessageTestHandler> handler =
+      new DevToolsMessageTestHandler();
+  handler->ExecuteTest();
+  ReleaseAndWaitForDestructor(handler);
+}

tests/shared/common/client_switches.cc

@@ -28,6 +28,7 @@ const char kShowUpdateRect[] = "show-update-rect";
 const char kSharedTextureEnabled[] = "shared-texture-enabled";
 const char kExternalBeginFrameEnabled[] = "external-begin-frame-enabled";
 const char kMouseCursorChangeDisabled[] = "mouse-cursor-change-disabled";
+const char kOffline[] = "offline";
 const char kRequestContextPerBrowser[] = "request-context-per-browser";
 const char kRequestContextSharedCache[] = "request-context-shared-cache";
 const char kBackgroundColor[] = "background-color";

tests/shared/common/client_switches.h

@@ -22,6 +22,7 @@ extern const char kShowUpdateRect[];
 extern const char kSharedTextureEnabled[];
 extern const char kExternalBeginFrameEnabled[];
 extern const char kMouseCursorChangeDisabled[];
+extern const char kOffline[];
 extern const char kRequestContextPerBrowser[];
 extern const char kRequestContextSharedCache[];
 extern const char kBackgroundColor[];

tools/gn_args.py

@@ -266,10 +266,6 @@ def GetRequiredArgs():
     # can't be enforced by assert().
     result['enable_linux_installer'] = False
 
-    # Use system fontconfig. This avoids a startup hang on Ubuntu 16.04.4 (see
-    # issue #2424).
-    result['use_bundled_fontconfig'] = False
-
     # Build without GTK dependencies (see issue #2014).
     result['use_gtk'] = False