Don't destroy RenderWidgetCompositor during DoDeferredClose

cc/trees/single_thread_proxy.h

Index: cc/trees/single_thread_proxy.h
diff --git a/cc/trees/single_thread_proxy.h b/cc/trees/single_thread_proxy.h
index b3a55b40d07568d0ca19aac90cdef0af65f0c185..a72a6eea1c8f1ed51dea1f53da6c9a4936619d94 100644
--- a/cc/trees/single_thread_proxy.h
+++ b/cc/trees/single_thread_proxy.h
@@ -35,6 +35,7 @@ class CC_EXPORT SingleThreadProxy : public Proxy,
   virtual void FinishAllRendering() OVERRIDE;
   virtual bool IsStarted() const OVERRIDE;
   virtual void SetLayerTreeHostClientReady() OVERRIDE;
+  virtual void SetLayerTreeHostClientFinished() OVERRIDE;
   virtual void SetVisible(bool visible) OVERRIDE;
   virtual const RendererCapabilities& GetRendererCapabilities() const OVERRIDE;
   virtual void SetNeedsAnimate() OVERRIDE;
@@ -149,6 +150,7 @@ class CC_EXPORT SingleThreadProxy : public Proxy,
   bool defer_commits_;
   bool commit_was_deferred_;
   bool commit_requested_;
+  bool host_client_finished_;
 
   base::WeakPtrFactory<SingleThreadProxy> weak_factory_;