Revert of Decouple GpuCompositorFrameSink from DisplayCompositor

components/display_compositor/gpu_compositor_frame_sink_delegate.h

-// Copyright 2017 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_DELEGATE_H_
-#define COMPONENTS_DISPLAY_COMPOSITOR_GPU_COMPOSITOR_FRAME_SINK_DELEGATE_H_
-
-namespace display_compositor {
-
-class GpuCompositorFrameSinkDelegate {
- public:
-  // We must avoid destroying a GpuCompositorFrameSink until both the display
-  // compositor host and the client drop their connection to avoid getting into
-  // a state where surfaces references are inconsistent.
-  virtual void OnClientConnectionLost(const cc::FrameSinkId& frame_sink_id,
-                                      bool destroy_compositor_frame_sink) = 0;
-  virtual void OnPrivateConnectionLost(const cc::FrameSinkId& frame_sink_id,
-                                       bool destroy_compositor_frame_sink) = 0;
-
- protected:
-  virtual ~GpuCompositorFrameSinkDelegate() {}
-};
-
-}  // namespace display_compositor
-
-#endif  // COMPONENTS_DISPLAY_COMPOSITOR_GPU_COMPOSITOR_FRAME_SINK_DELEGATE_H_