add support for forcing compositing mode

webkit/glue/webpreferences.cc

-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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.
 
 #include "webkit/glue/webpreferences.h"
 
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebRuntimeFeatures.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebKit.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebSettings.h"
@@ skipping 49 matching lines @@
       allow_universal_access_from_file_urls(false),
       allow_file_access_from_file_urls(false),
       webaudio_enabled(false),
       experimental_webgl_enabled(false),
       gl_multisampling_enabled(true),
       show_composited_layer_borders(false),
       show_composited_layer_tree(false),
       show_fps_counter(false),
       asynchronous_spell_checking_enabled(true),
       accelerated_compositing_enabled(false),
+      force_compositing_mode(false),
       composite_to_texture_enabled(false),
       accelerated_layers_enabled(false),
       accelerated_video_enabled(false),
       accelerated_2d_canvas_enabled(false),
       accelerated_plugins_enabled(false),
       memory_info_enabled(false),
       interactive_form_validation_enabled(true),
       fullscreen_enabled(false) {
 }
 
@@ skipping 87 matching lines @@
   // Display an FPS indicator if requested on the command line.
   settings->setShowFPSCounter(show_fps_counter);
 
   // Display the current compositor tree as overlay if requested on
   // the command line
   settings->setShowPlatformLayerTree(show_composited_layer_tree);
 
   // Enable gpu-accelerated compositing if requested on the command line.
   settings->setAcceleratedCompositingEnabled(accelerated_compositing_enabled);
 
+  // Always enter compositing if requested on the command line.
+  settings->setForceCompositingMode(force_compositing_mode);
+
   // Enable composite to offscreen texture if requested on the command line.
   settings->setCompositeToTextureEnabled(composite_to_texture_enabled);
 
   // Enable gpu-accelerated 2d canvas if requested on the command line.
   settings->setAccelerated2dCanvasEnabled(accelerated_2d_canvas_enabled);
 
   // Enabling accelerated layers from the command line enabled accelerated
   // 3D CSS, Video, and Animations.
   settings->setAcceleratedCompositingFor3DTransformsEnabled(
       accelerated_layers_enabled);
@@ skipping 23 matching lines @@
 
   // Tabs to link is not part of the settings. WebCore calls
   // ChromeClient::tabsToLinks which is part of the glue code.
   web_view->setTabsToLinks(tabs_to_links);
 
   settings->setInteractiveFormValidationEnabled(
       interactive_form_validation_enabled);
 
   settings->setFullScreenEnabled(fullscreen_enabled);
 }