Turn off computation of the interest rect in cc in synchronized paint mode.

third_party/WebKit/Source/web/WebRuntimeFeatures.cpp

 /*
  * Copyright (C) 2013 Google Inc. 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
@@ skipping 208 matching lines @@
 void WebRuntimeFeatures::enableScriptedSpeech(bool enable)
 {
     RuntimeEnabledFeatures::setScriptedSpeechEnabled(enable);
 }
 
 void WebRuntimeFeatures::enableSlimmingPaintV2(bool enable)
 {
     RuntimeEnabledFeatures::setSlimmingPaintV2Enabled(enable);
 }
 
+void WebRuntimeFeatures::enableBlinkSynchronizedPainting(bool enable)
+{
+    RuntimeEnabledFeatures::setSlimmingPaintSynchronizedPaintingEnabled(enable);
+}
+
 void WebRuntimeFeatures::enableTouch(bool enable)
 {
     RuntimeEnabledFeatures::setTouchEnabled(enable);
 }
 
 void WebRuntimeFeatures::enableTouchIconLoading(bool enable)
 {
     RuntimeEnabledFeatures::setTouchIconLoadingEnabled(enable);
 }
 
@@ skipping 86 matching lines @@
 {
     RuntimeEnabledFeatures::setNewMediaPlaybackUiEnabled(enable);
 }
 
 void WebRuntimeFeatures::enablePresentationAPI(bool enable)
 {
     RuntimeEnabledFeatures::setPresentationEnabled(enable);
 }
 
 } // namespace blink