Change default force composite setting to true

Source/web/WebViewImpl.cpp

 /*
  * Copyright (C) 2011, 2012 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 3789 matching lines @@
         m_client->scheduleAnimation();
 }
 
 void WebViewImpl::setIsAcceleratedCompositingActive(bool active)
 {
     blink::Platform::current()->histogramEnumeration("GPU.setIsAcceleratedCompositingActive", active * 2 + m_isAcceleratedCompositingActive, 4);
 
     if (m_isAcceleratedCompositingActive == active)
         return;
 
+    if (!m_client)

[enne (OOO), 2014/05/15 19:29:21]

Other parts of WebViewImpl are robust to a missing client.  This part needs to
be too now once the force composite by default flag is flipped and this code
path is hit in content unit tests.

+        return;
+
     if (!active) {
         m_isAcceleratedCompositingActive = false;
         // We need to finish all GL rendering before sending didDeactivateCompositor() to prevent
         // flickering when compositing turns off. This is only necessary if we're not in
         // force-compositing-mode.
         if (m_layerTreeView && !page()->settings().forceCompositingMode())
             m_layerTreeView->finishAllRendering();
         m_client->didDeactivateCompositor();
         if (!m_layerTreeViewCommitsDeferred
             && blink::Platform::current()->isThreadedCompositingEnabled()) {
@@ skipping 244 matching lines @@
     const PageScaleConstraints& constraints = m_pageScaleConstraintsSet.pageDefinedConstraints();
 
     if (!mainFrameImpl() || !mainFrameImpl()->frameView())
         return false;
 
     return mainFrameImpl()->frameView()->layoutSize().width() == m_size.width
         || (constraints.minimumScale == constraints.maximumScale && constraints.minimumScale != -1);
 }
 
 } // namespace blink