Add support for loading extensions (issue #1947)

- Add CefRequestContext::LoadExtension, CefExtension, CefExtensionHandler and
  related methods/interfaces.
- Add chrome://extensions-support that lists supported Chrome APIs.
- Add CefBrowserHost::SetAutoResizeEnabled and CefDisplayHandler::OnAutoResize
  to support browser resize based on preferred web contents size.
- views: Add support for custom CefMenuButton popups.
- cefclient: Run with `--load-extension=set_page_color` command-line flag for
  an extension loading example. Add `--use-views` on Windows and Linux for an
  even better example.

libcef_dll/cpptoc/extension_cpptoc.cc

@@ -0,0 +1,181 @@
+// Copyright (c) 2017 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.
+//
+// $hash=59b3e055a5cdd19a3af4b3e313f2d7095bd578e5$
+//
+
+#include "libcef_dll/cpptoc/extension_cpptoc.h"
+#include "libcef_dll/cpptoc/dictionary_value_cpptoc.h"
+#include "libcef_dll/cpptoc/request_context_cpptoc.h"
+#include "libcef_dll/ctocpp/extension_handler_ctocpp.h"
+
+namespace {
+
+// MEMBER FUNCTIONS - Body may be edited by hand.
+
+cef_string_userfree_t CEF_CALLBACK
+extension_get_identifier(struct _cef_extension_t* self) {
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  DCHECK(self);
+  if (!self)
+    return NULL;
+
+  // Execute
+  CefString _retval = CefExtensionCppToC::Get(self)->GetIdentifier();
+
+  // Return type: string
+  return _retval.DetachToUserFree();
+}
+
+cef_string_userfree_t CEF_CALLBACK
+extension_get_path(struct _cef_extension_t* self) {
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  DCHECK(self);
+  if (!self)
+    return NULL;
+
+  // Execute
+  CefString _retval = CefExtensionCppToC::Get(self)->GetPath();
+
+  // Return type: string
+  return _retval.DetachToUserFree();
+}
+
+struct _cef_dictionary_value_t* CEF_CALLBACK
+extension_get_manifest(struct _cef_extension_t* self) {
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  DCHECK(self);
+  if (!self)
+    return NULL;
+
+  // Execute
+  CefRefPtr<CefDictionaryValue> _retval =
+      CefExtensionCppToC::Get(self)->GetManifest();
+
+  // Return type: refptr_same
+  return CefDictionaryValueCppToC::Wrap(_retval);
+}
+
+int CEF_CALLBACK extension_is_same(struct _cef_extension_t* self,
+                                   struct _cef_extension_t* that) {
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  DCHECK(self);
+  if (!self)
+    return 0;
+  // Verify param: that; type: refptr_same
+  DCHECK(that);
+  if (!that)
+    return 0;
+
+  // Execute
+  bool _retval =
+      CefExtensionCppToC::Get(self)->IsSame(CefExtensionCppToC::Unwrap(that));
+
+  // Return type: bool
+  return _retval;
+}
+
+struct _cef_extension_handler_t* CEF_CALLBACK
+extension_get_handler(struct _cef_extension_t* self) {
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  DCHECK(self);
+  if (!self)
+    return NULL;
+
+  // Execute
+  CefRefPtr<CefExtensionHandler> _retval =
+      CefExtensionCppToC::Get(self)->GetHandler();
+
+  // Return type: refptr_diff
+  return CefExtensionHandlerCToCpp::Unwrap(_retval);
+}
+
+struct _cef_request_context_t* CEF_CALLBACK
+extension_get_loader_context(struct _cef_extension_t* self) {
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  DCHECK(self);
+  if (!self)
+    return NULL;
+
+  // Execute
+  CefRefPtr<CefRequestContext> _retval =
+      CefExtensionCppToC::Get(self)->GetLoaderContext();
+
+  // Return type: refptr_same
+  return CefRequestContextCppToC::Wrap(_retval);
+}
+
+int CEF_CALLBACK extension_is_loaded(struct _cef_extension_t* self) {
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  DCHECK(self);
+  if (!self)
+    return 0;
+
+  // Execute
+  bool _retval = CefExtensionCppToC::Get(self)->IsLoaded();
+
+  // Return type: bool
+  return _retval;
+}
+
+void CEF_CALLBACK extension_unload(struct _cef_extension_t* self) {
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  DCHECK(self);
+  if (!self)
+    return;
+
+  // Execute
+  CefExtensionCppToC::Get(self)->Unload();
+}
+
+}  // namespace
+
+// CONSTRUCTOR - Do not edit by hand.
+
+CefExtensionCppToC::CefExtensionCppToC() {
+  GetStruct()->get_identifier = extension_get_identifier;
+  GetStruct()->get_path = extension_get_path;
+  GetStruct()->get_manifest = extension_get_manifest;
+  GetStruct()->is_same = extension_is_same;
+  GetStruct()->get_handler = extension_get_handler;
+  GetStruct()->get_loader_context = extension_get_loader_context;
+  GetStruct()->is_loaded = extension_is_loaded;
+  GetStruct()->unload = extension_unload;
+}
+
+template <>
+CefRefPtr<CefExtension>
+CefCppToCRefCounted<CefExtensionCppToC, CefExtension, cef_extension_t>::
+    UnwrapDerived(CefWrapperType type, cef_extension_t* s) {
+  NOTREACHED() << "Unexpected class type: " << type;
+  return NULL;
+}
+
+#if DCHECK_IS_ON()
+template <>
+base::AtomicRefCount
+    CefCppToCRefCounted<CefExtensionCppToC, CefExtension, cef_extension_t>::
+        DebugObjCt ATOMIC_DECLARATION;
+#endif
+
+template <>
+CefWrapperType CefCppToCRefCounted<CefExtensionCppToC,
+                                   CefExtension,
+                                   cef_extension_t>::kWrapperType =
+    WT_EXTENSION;