| Index: cc/output/compositor_frame_sink.h
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| diff --git a/cc/output/compositor_frame_sink.h b/cc/output/compositor_frame_sink.h
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| index f8b7a47b4e6c97fc06934a4a4062377f270e1e45..28b72581b5e47d7a379ada55dd5ca468341da83c 100644
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| --- a/cc/output/compositor_frame_sink.h
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| +++ b/cc/output/compositor_frame_sink.h
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| @@ -25,6 +25,7 @@ class GpuMemoryBufferManager;
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|  
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|  namespace cc {
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|  
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| +struct BeginFrameAck;
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|  class CompositorFrame;
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|  class CompositorFrameSinkClient;
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|  class LocalSurfaceId;
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| @@ -121,6 +122,10 @@ class CC_EXPORT CompositorFrameSink {
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|    // processed in order to unthrottle the next frame.
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|    virtual void SubmitCompositorFrame(CompositorFrame frame) = 0;
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|  
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| +  // Signals that a BeginFrame issued by the BeginFrameSource provided to the
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| +  // client did not lead to a CompositorFrame submission.
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| +  virtual void DidNotProduceFrame(const BeginFrameAck& ack) = 0;
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| +
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|   protected:
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|    // Bound to the ContextProvider to hear about when it is lost and inform the
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|    // |client_|.
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| 
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