Integrate r128344 and r128253 from WebKit

cc/CCLayerTreeHostImpl.cpp

Index: cc/CCLayerTreeHostImpl.cpp
diff --git a/cc/CCLayerTreeHostImpl.cpp b/cc/CCLayerTreeHostImpl.cpp
index 8abbd1ad49fdcc8883d6add2b7d8f8cf9531dc65..e306e440ae3e863a3283cb85c65697a9f098c168 100644
--- a/cc/CCLayerTreeHostImpl.cpp
+++ b/cc/CCLayerTreeHostImpl.cpp
@@ -500,8 +500,8 @@ void CCLayerTreeHostImpl::releaseContentsTextures()
 {
     if (m_contentsTexturesPurged)
         return;
-    m_resourceProvider->deleteOwnedResources(CCRenderer::ContentPool);
-    m_contentsTexturesPurged = true;
+    m_client->releaseContentsTexturesOnImplThread();
+    setContentsTexturesPurged();
     m_client->setNeedsCommitOnImplThread();
     m_client->onCanDrawStateChanged(canDraw());
 }
@@ -712,6 +712,12 @@ bool CCLayerTreeHostImpl::initializeRenderer(PassOwnPtr<CCGraphicsContext> conte
     return m_renderer;
 }
 
+void CCLayerTreeHostImpl::setContentsTexturesPurged()
+{
+    m_contentsTexturesPurged = true;
+    m_client->onCanDrawStateChanged(canDraw());
+}
+
 void CCLayerTreeHostImpl::resetContentsTexturesPurged()
 {
     m_contentsTexturesPurged = false;