chrome: Add ability to handle chrome menu/keyboard commands (fixes issue #3280)

This change adds a CefCommandHandler::OnChromeCommand callback for optionally
handling Chrome commands triggered via menus or keyboard shortcuts. Supported
command IDs are listed in a new cef_command_ids.h header file.

To test: Run `cefclient --enable-chrome-runtime --hide-controls`. Most commands
will blocked and removed from context menus.

include/capi/cef_client_capi.h

@@ -33,7 +33,7 @@
 // by hand. See the translator.README.txt file in the tools directory for
 // more information.
 //
-// $hash=8b099ca3b9cfbd41840cdf64586a0b884abaffae$
+// $hash=7df3c13b75072c2ad5061cd3a344811222798903$
 //
 
 #ifndef CEF_INCLUDE_CAPI_CEF_CLIENT_CAPI_H_
@@ -42,6 +42,7 @@
 
 #include "include/capi/cef_audio_handler_capi.h"
 #include "include/capi/cef_base_capi.h"
+#include "include/capi/cef_command_handler_capi.h"
 #include "include/capi/cef_context_menu_handler_capi.h"
 #include "include/capi/cef_dialog_handler_capi.h"
 #include "include/capi/cef_display_handler_capi.h"
@@ -78,6 +79,13 @@ typedef struct _cef_client_t {
   struct _cef_audio_handler_t*(CEF_CALLBACK* get_audio_handler)(
       struct _cef_client_t* self);
 
+  ///
+  // Return the handler for commands. If no handler is provided the default
+  // implementation will be used.
+  ///
+  struct _cef_command_handler_t*(CEF_CALLBACK* get_command_handler)(
+      struct _cef_client_t* self);
+
   ///
   // Return the handler for context menus. If no handler is provided the default
   // implementation will be used.

include/capi/cef_command_handler_capi.h

@@ -0,0 +1,80 @@
+// Copyright (c) 2022 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.
+//
+// $hash=54332b79c057df9c8f3be56cc77f1daf877b3ac1$
+//
+
+#ifndef CEF_INCLUDE_CAPI_CEF_COMMAND_HANDLER_CAPI_H_
+#define CEF_INCLUDE_CAPI_CEF_COMMAND_HANDLER_CAPI_H_
+#pragma once
+
+#include "include/capi/cef_base_capi.h"
+#include "include/capi/cef_browser_capi.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+///
+// Implement this structure to handle events related to commands. The functions
+// of this structure will be called on the UI thread.
+///
+typedef struct _cef_command_handler_t {
+  ///
+  // Base structure.
+  ///
+  cef_base_ref_counted_t base;
+
+  ///
+  // Called to execute a Chrome command triggered via menu selection or keyboard
+  // shortcut. Values for |command_id| can be found in the cef_command_ids.h
+  // file. |disposition| provides information about the intended command target.
+  // Return true (1) if the command was handled or false (0) for the default
+  // implementation. For context menu commands this will be called after
+  // cef_context_menu_handler_t::OnContextMenuCommand. Only used with the Chrome
+  // runtime.
+  ///
+  int(CEF_CALLBACK* on_chrome_command)(
+      struct _cef_command_handler_t* self,
+      struct _cef_browser_t* browser,
+      int command_id,
+      cef_window_open_disposition_t disposition);
+} cef_command_handler_t;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // CEF_INCLUDE_CAPI_CEF_COMMAND_HANDLER_CAPI_H_