Support for '--force-compositing-mode', see WebKit bug 56156

BUG=
TEST=


Review URL: http://codereview.chromium.org/6665057

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@78904 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 16 insertions, 2 deletions

diff --git a/chrome/browser/tab_contents/render_view_host_delegate_helper.cc b/chrome/browser/tab_contents/render_view_host_delegate_helper.cc
index f5d686b..f88dddb 100644
--- a/chrome/browser/tab_contents/render_view_host_delegate_helper.cc
+++ b/chrome/browser/tab_contents/render_view_host_delegate_helper.cc
@@ -293,6 +293,8 @@ WebPreferences RenderViewHostDelegateHelper::GetWebkitPrefs(
     web_prefs.accelerated_compositing_enabled =
         gpu_enabled() &&
         !command_line.HasSwitch(switches::kDisableAcceleratedCompositing);
+    web_prefs.force_compositing_mode =
+        command_line.HasSwitch(switches::kForceCompositingMode);
     web_prefs.accelerated_2d_canvas_enabled =
         gpu_enabled() &&
         command_line.HasSwitch(switches::kEnableAccelerated2dCanvas);
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index 01e4d6a..7286e94 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -611,6 +611,10 @@ const char kFirstRun[]                      = "first-run";
 // timed out, etc. Useful for testing.
 const char kForceAppsPromoVisible[]         = "force-apps-promo-visible";
 
+// If accelerated compositing is supported, always enter compositing mode for
+// the base layer even when compositing is not strictly required.
+const char kForceCompositingMode[]          = "force-compositing-mode";
+
 // Some field tests may rendomized in the browser, and the randomly selected
 // outcome needs to be propogated to the renderer.  For instance, this is used
 // to modify histograms recorded in the renderer, or to get the renderer to
diff --git a/chrome/common/chrome_switches.h b/chrome/common/chrome_switches.h
index e7bc4da..7550cff 100644
--- a/chrome/common/chrome_switches.h
+++ b/chrome/common/chrome_switches.h
@@ -182,6 +182,7 @@ extern const char kFileDescriptorLimit[];
 extern const char kFocusExistingTabOnOpen[];
 extern const char kFirstRun[];
 extern const char kForceAppsPromoVisible[];
+extern const char kForceCompositingMode[];
 extern const char kForceFieldTestNameAndValue[];
 extern const char kForceRendererAccessibility[];
 extern const char kForceStubLibcros[];
diff --git a/chrome/common/render_messages.cc b/chrome/common/render_messages.cc
index c05d761..52d7280 100644
--- a/chrome/common/render_messages.cc
+++ b/chrome/common/render_messages.cc
@@ -410,6 +410,7 @@ void ParamTraits<WebPreferences>::Write(Message* m, const param_type& p) {
   WriteParam(m, p.show_composited_layer_tree);
   WriteParam(m, p.show_fps_counter);
   WriteParam(m, p.accelerated_compositing_enabled);
+  WriteParam(m, p.force_compositing_mode);
   WriteParam(m, p.composite_to_texture_enabled);
   WriteParam(m, p.accelerated_2d_canvas_enabled);
   WriteParam(m, p.accelerated_plugins_enabled);
@@ -470,6 +471,7 @@ bool ParamTraits<WebPreferences>::Read(const Message* m, void** iter,
       ReadParam(m, iter, &p->show_composited_layer_tree) &&
       ReadParam(m, iter, &p->show_fps_counter) &&
       ReadParam(m, iter, &p->accelerated_compositing_enabled) &&
+      ReadParam(m, iter, &p->force_compositing_mode) &&
       ReadParam(m, iter, &p->composite_to_texture_enabled) &&
       ReadParam(m, iter, &p->accelerated_2d_canvas_enabled) &&
       ReadParam(m, iter, &p->accelerated_plugins_enabled) &&
diff --git a/webkit/glue/webpreferences.cc b/webkit/glue/webpreferences.cc
index ab359a2..116d43d 100644
--- a/webkit/glue/webpreferences.cc
+++ b/webkit/glue/webpreferences.cc
@@ -1,4 +1,4 @@
-// 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.
 
@@ -68,6 +68,7 @@ WebPreferences::WebPreferences()
       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),
@@ -175,6 +176,9 @@ void WebPreferences::Apply(WebView* web_view) const {
   // 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);
 
diff --git a/webkit/glue/webpreferences.h b/webkit/glue/webpreferences.h
index 0d37d39..c373504 100644
--- a/webkit/glue/webpreferences.h
+++ b/webkit/glue/webpreferences.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2006-2008 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.
 //
@@ -74,6 +74,7 @@ struct WebPreferences {
   bool show_fps_counter;
   bool asynchronous_spell_checking_enabled;
   bool accelerated_compositing_enabled;
+  bool force_compositing_mode;
   bool composite_to_texture_enabled;
   bool accelerated_layers_enabled;
   bool accelerated_video_enabled;