Add a command line switch to control accelerated 2d canvas

webkit/glue/webpreferences.h

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // A struct for managing webkit's settings.
 //
 // Adding new values to this class probably involves updating
 // WebKit::WebSettings, common/render_messages.h, and
 // browser/profile.cc.
 
@@ skipping 46 matching lines @@
   bool tabs_to_links;
 
   bool user_style_sheet_enabled;
   GURL user_style_sheet_location;
   bool author_and_user_styles_enabled;
   bool allow_universal_access_from_file_urls;
   bool allow_file_access_from_file_urls;
   bool experimental_webgl_enabled;
   bool show_composited_layer_borders;
   bool accelerated_compositing_enabled;
+  bool accelerated_2d_canvas_enabled;
   bool enable_html5_parser;
   bool memory_info_enabled;
 
   // We try to keep the default values the same as the default values in
   // chrome, except for the cases where it would require lots of extra work for
   // the embedder to use the same default value.
   WebPreferences()
       : standard_font_family(L"Times New Roman"),
         fixed_font_family(L"Courier New"),
         serif_font_family(L"Times New Roman"),
@@ skipping 26 matching lines @@
         databases_enabled(false),
         application_cache_enabled(false),
         tabs_to_links(true),
         user_style_sheet_enabled(false),
         author_and_user_styles_enabled(true),
         allow_universal_access_from_file_urls(false),
         allow_file_access_from_file_urls(false),
         experimental_webgl_enabled(false),
         show_composited_layer_borders(false),
         accelerated_compositing_enabled(false),
+        accelerated_2d_canvas_enabled(false),
         enable_html5_parser(true),
         memory_info_enabled(false) {
   }
 
   void Apply(WebKit::WebView* web_view) const;
 };
 
 #endif  // WEBKIT_GLUE_WEBPREFERENCES_H__