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

cc/surfaces/surface_factory.h

 // Copyright 2014 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_SURFACE_FACTORY_H_
 #define CC_SURFACES_SURFACE_FACTORY_H_
 
 #include <memory>
 #include <set>
 
@@ skipping 69 matching lines @@
   SurfaceManager* manager() { return manager_; }
 
   Surface* current_surface_for_testing() { return current_surface_.get(); }
 
   // This can be set to false if resources from this SurfaceFactory don't need
   // to have sync points set on them when returned from the Display, for
   // example if the Display shares a context with the creator.
   bool needs_sync_points() const { return needs_sync_points_; }
   void set_needs_sync_points(bool needs) { needs_sync_points_ = needs; }
 
+  void OnBadFrameReceived();
+
  private:
   // PendingFrameObserver implementation.
   void OnReferencedSurfacesChanged(
       Surface* surface,
       const std::vector<SurfaceId>* active_referenced_surfaces,
       const std::vector<SurfaceId>* pending_referenced_surfaces) override;
   void OnSurfaceActivated(Surface* surface) override;
   void OnSurfaceDependenciesChanged(
       Surface* surface,
       const SurfaceDependencies& added_dependencies,
@@ skipping 11 matching lines @@
   bool seen_first_frame_activation_ = false;
   std::unique_ptr<Surface> current_surface_;
   base::WeakPtrFactory<SurfaceFactory> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SurfaceFactory);
 };
 
 }  // namespace cc
 
 #endif  // CC_SURFACES_SURFACE_FACTORY_H_