Merge 98392 - LayerRendererChromium::setVisible called needlessly without a visibility change

Source/WebCore/platform/graphics/chromium/cc/CCLayerTreeHostImpl.cpp

 /*
  * Copyright (C) 2011 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:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 29 matching lines @@
 
 PassOwnPtr<CCLayerTreeHostImpl> CCLayerTreeHostImpl::create(const CCSettings& settings)
 {
     return adoptPtr(new CCLayerTreeHostImpl(settings));
 }
 
 CCLayerTreeHostImpl::CCLayerTreeHostImpl(const CCSettings& settings)
     : m_sourceFrameNumber(-1)
     , m_frameNumber(0)
     , m_settings(settings)
+    , m_visible(true)
 {
     ASSERT(CCProxy::isImplThread());
 }
 
 CCLayerTreeHostImpl::~CCLayerTreeHostImpl()
 {
     ASSERT(CCProxy::isImplThread());
     TRACE_EVENT("CCLayerTreeHostImpl::~CCLayerTreeHostImpl()", this, 0);
     if (m_layerRenderer)
         m_layerRenderer->close();
@@ skipping 55 matching lines @@
     m_layerRenderer->getFramebufferPixels(pixels, rect);
 }
 
 void CCLayerTreeHostImpl::setRootLayer(PassRefPtr<CCLayerImpl> layer)
 {
     m_rootLayerImpl = layer;
 }
 
 void CCLayerTreeHostImpl::setVisible(bool visible)
 {
+    if (m_visible == visible)
+        return;
+    m_visible = visible;
+
     if (m_layerRenderer)
         m_layerRenderer->setVisible(visible);
 }
 
 bool CCLayerTreeHostImpl::initializeLayerRenderer(PassRefPtr<GraphicsContext3D> context)
 {
     OwnPtr<LayerRendererChromium> layerRenderer;
     layerRenderer = LayerRendererChromium::create(this, context);
 
     // If creation failed, and we had asked for accelerated painting, disable accelerated painting
@@ skipping 43 matching lines @@
         info.scrollDelta = rootLayer()->scrollDelta();
         scrollInfo->append(info);
 
         rootLayer()->setScrollPosition(rootLayer()->scrollPosition() + rootLayer()->scrollDelta());
         rootLayer()->setScrollDelta(IntSize());
     }
     return scrollInfo.release();
 }
 
 }