cc: Route offscreen context creation for compositor to the browser.

cc/thread_proxy.h

Index: cc/thread_proxy.h
diff --git a/cc/thread_proxy.h b/cc/thread_proxy.h
index 9e383bbc7b0ab6caedc5a5d39272385023498528..504dca3959c4448e9b535d4ae99df0157be92bde 100644
--- a/cc/thread_proxy.h
+++ b/cc/thread_proxy.h
@@ -17,6 +17,7 @@
 
 namespace cc {
 
+class ContextProvider;
 class InputHandler;
 class LayerTreeHost;
 class ResourceUpdateQueue;
@@ -123,7 +124,7 @@ private:
         bool commitPending;
     };
     void forceBeginFrameOnImplThread(CompletionEvent*);
-    void beginFrameCompleteOnImplThread(CompletionEvent*, ResourceUpdateQueue*);
+    void beginFrameCompleteOnImplThread(CompletionEvent*, ResourceUpdateQueue*, scoped_refptr<cc::ContextProvider> offscreenContextProvider);
     void beginFrameAbortedOnImplThread();
     void requestReadbackOnImplThread(ReadbackRequest*);
     void requestStartPageScaleAnimationOnImplThread(gfx::Vector2d targetOffset, bool useAnchor, float scale, base::TimeDelta duration);
@@ -137,7 +138,7 @@ private:
     void manageTilesOnImplThread();
     void setFullRootLayerDamageOnImplThread();
     void acquireLayerTexturesForMainThreadOnImplThread(CompletionEvent*);
-    void recreateOutputSurfaceOnImplThread(CompletionEvent*, scoped_ptr<OutputSurface>, bool* recreateSucceeded, RendererCapabilities*);
+    void recreateOutputSurfaceOnImplThread(CompletionEvent*, scoped_ptr<OutputSurface>, scoped_refptr<cc::ContextProvider> offscreenContextProvider, bool* recreateSucceeded, RendererCapabilities*);
     void renderingStatsOnImplThread(CompletionEvent*, RenderingStats*);
     ScheduledActionDrawAndSwapResult scheduledActionDrawAndSwapInternal(bool forcedDraw);
     void forceSerializeOnSwapBuffersOnImplThread(CompletionEvent*);
@@ -153,6 +154,7 @@ private:
     bool m_animateRequested; // Set only when setNeedsAnimate is called.
     bool m_commitRequested; // Set only when setNeedsCommit is called.
     bool m_commitRequestSentToImplThread; // Set by setNeedsCommit and setNeedsAnimate.
+    bool m_createdOffscreenContextProvider; // Set by beginFrame.
     base::CancelableClosure m_outputSurfaceRecreationCallback;
     LayerTreeHost* m_layerTreeHost;
     bool m_rendererInitialized;