Move FrameSink hierarchy registration to DisplayCompositor interface

components/display_compositor/gpu_compositor_frame_sink.h

 // Copyright 2015 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 COMPONENTS_DISPLAY_COMPOSITOR_GPU_COMPOSITOR_FRAME_SINK_H_
 #define COMPONENTS_DISPLAY_COMPOSITOR_GPU_COMPOSITOR_FRAME_SINK_H_
 
 #include <memory>
 #include <vector>
 
@@ skipping 28 matching lines @@
   // cc::mojom::MojoCompositorFrameSink:
   void EvictFrame() override;
   void SetNeedsBeginFrame(bool needs_begin_frame) override;
   void SubmitCompositorFrame(const cc::LocalSurfaceId& local_surface_id,
                              cc::CompositorFrame frame) override;
   void Require(const cc::LocalSurfaceId& local_surface_id,
                const cc::SurfaceSequence& sequence) override;
   void Satisfy(const cc::SurfaceSequence& sequence) override;
 
   // cc::mojom::MojoCompositorFrameSinkPrivate:
-  void AddChildFrameSink(const cc::FrameSinkId& child_frame_sink_id) override;
-  void RemoveChildFrameSink(
-      const cc::FrameSinkId& child_frame_sink_id) override;
   void RequestCopyOfSurface(
       std::unique_ptr<cc::CopyOutputRequest> request) override;
 
  private:
   // cc::CompositorFrameSinkSupportClient implementation:
   void DidReceiveCompositorFrameAck() override;
   void OnBeginFrame(const cc::BeginFrameArgs& args) override;
   void ReclaimResources(const cc::ReturnedResourceArray& resources) override;
   void WillDrawSurface(const cc::LocalSurfaceId& local_surface_id,
                        const gfx::Rect& damage_rect) override;
@@ skipping 12 matching lines @@
       compositor_frame_sink_binding_;
   mojo::Binding<cc::mojom::MojoCompositorFrameSinkPrivate>
       compositor_frame_sink_private_binding_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuCompositorFrameSink);
 };
 
 }  // namespace display_compositor
 
 #endif  // COMPONENTS_DISPLAY_COMPOSITOR_GPU_COMPOSITOR_FRAME_SINK_H_