Move FrameSink hierarchy registration to DisplayCompositor interface

components/display_compositor/gpu_compositor_frame_sink.cc

 // 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.
 
 #include "components/display_compositor/gpu_compositor_frame_sink.h"
 
 #include "cc/surfaces/surface_reference.h"
 
 namespace display_compositor {
 
@@ skipping 48 matching lines @@
 
 void GpuCompositorFrameSink::Satisfy(const cc::SurfaceSequence& sequence) {
   support_->Satisfy(sequence);
 }
 
 void GpuCompositorFrameSink::DidReceiveCompositorFrameAck() {
   if (client_)
     client_->DidReceiveCompositorFrameAck();
 }
 
-void GpuCompositorFrameSink::AddChildFrameSink(
-    const cc::FrameSinkId& child_frame_sink_id) {
-  support_->AddChildFrameSink(child_frame_sink_id);
-}
-
-void GpuCompositorFrameSink::RemoveChildFrameSink(
-    const cc::FrameSinkId& child_frame_sink_id) {
-  support_->RemoveChildFrameSink(child_frame_sink_id);
-}
-
 void GpuCompositorFrameSink::RequestCopyOfSurface(
     std::unique_ptr<cc::CopyOutputRequest> request) {
   support_->RequestCopyOfSurface(std::move(request));
 }
 
 void GpuCompositorFrameSink::OnBeginFrame(const cc::BeginFrameArgs& args) {
   if (client_)
     client_->OnBeginFrame(args);
 }
 
@@ skipping 18 matching lines @@
 }
 
 void GpuCompositorFrameSink::OnPrivateConnectionLost() {
   private_connection_lost_ = true;
   // Request destruction of |this| only if both connections are lost.
   delegate_->OnPrivateConnectionLost(support_->frame_sink_id(),
                                      client_connection_lost_);
 }
 
 }  // namespace display_compositor