DisplayCompositor should enforce invariant that frame size and device scale factor are fixed

cc/surfaces/compositor_frame_sink_support_client.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_SURFACES_COMPOSITOR_FRAME_SINK_SUPPORT_CLIENT_H_
 #define CC_SURFACES_COMPOSITOR_FRAME_SINK_SUPPORT_CLIENT_H_
 
 #include "cc/resources/returned_resource.h"
 
 namespace gfx {
@@ skipping 20 matching lines @@
   // Notification for the client to generate a CompositorFrame.
   virtual void OnBeginFrame(const BeginFrameArgs& args) = 0;
 
   // Returns resources sent to SubmitCompositorFrame to be reused or freed.
   virtual void ReclaimResources(const ReturnedResourceArray& resources) = 0;
 
   // Called when surface is being scheduled for a draw.
   virtual void WillDrawSurface(const LocalSurfaceId& local_surface_id,
                                const gfx::Rect& damage_rect) = 0;
 
+  virtual void OnBadFrameReceived() {}
+
  protected:
   virtual ~CompositorFrameSinkSupportClient() {}
 };
 
 }  // namespace cc
 
 #endif  // CC_SURFACES_COMPOSITOR_FRAME_SINK_SUPPORT_CLIENT_H_