Merge 121450 - [chromium] Should schedule a commit when dropping contents textures

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 138 matching lines @@
     if (m_rootLayerImpl)
         clearRenderSurfaces();
 }
 
 void CCLayerTreeHostImpl::beginCommit()
 {
 }
 
 void CCLayerTreeHostImpl::commitComplete()
 {
+    TRACE_EVENT0("cc", "CCLayerTreeHostImpl::commitComplete");
     // Recompute max scroll position; must be after layer content bounds are
     // updated.
     updateMaxScrollPosition();
     m_contentsTexturesWerePurgedSinceLastCommit = false;
 }
 
 bool CCLayerTreeHostImpl::canDraw()
 {
-    if (!m_rootLayerImpl)
+    if (!m_rootLayerImpl) {
+        TRACE_EVENT_INSTANT0("cc", "CCLayerTreeHostImpl::canDraw no root layer");
         return false;
-    if (viewportSize().isEmpty())
+    }
+    if (viewportSize().isEmpty()) {
+        TRACE_EVENT_INSTANT0("cc", "CCLayerTreeHostImpl::canDraw empty viewport");
         return false;
-    if (!m_layerRenderer)
+    }
+    if (!m_layerRenderer) {
+        TRACE_EVENT_INSTANT0("cc", "CCLayerTreeHostImpl::canDraw no layerRenderer");
         return false;
-    if (m_contentsTexturesWerePurgedSinceLastCommit)
+    }
+    if (m_contentsTexturesWerePurgedSinceLastCommit) {
+        TRACE_EVENT_INSTANT0("cc", "CCLayerTreeHostImpl::canDraw contents textures purged");
         return false;
+    }
     return true;
 }
 
 CCGraphicsContext* CCLayerTreeHostImpl::context() const
 {
     return m_context.get();
 }
 
 void CCLayerTreeHostImpl::animate(double monotonicTime, double wallClockTime)
 {
@@ skipping 217 matching lines @@
         return false;
 
     // If we return true, then we expect drawLayers() to be called before this function is called again.
     return true;
 }
 
 void CCLayerTreeHostImpl::releaseContentsTextures()
 {
     contentsTextureAllocator()->deleteAllTextures();
     m_contentsTexturesWerePurgedSinceLastCommit = true;
+    m_client->setNeedsCommitOnImplThread();
 }
 
 void CCLayerTreeHostImpl::setMemoryAllocationLimitBytes(size_t bytes)
 {
     if (m_memoryAllocationLimitBytes == bytes)
         return;
     m_memoryAllocationLimitBytes = bytes;
 
     ASSERT(bytes);
     m_client->setNeedsCommitOnImplThread();
@@ skipping 662 matching lines @@
         return;
 
     bool isContinuing = m_activeGestureAnimation->animate(monotonicTime);
     if (isContinuing)
         m_client->setNeedsRedrawOnImplThread();
     else
         m_activeGestureAnimation.clear();
 }
 
 } // namespace WebCore