[cc] Forward BeginFrameAcks through DirectCFS and CFSSupport.

cc/test/fake_compositor_frame_sink_client.cc

 // Copyright 2013 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 "cc/output/compositor_frame_sink.h"
 #include "cc/test/fake_compositor_frame_sink_client.h"
 
 namespace cc {
 
+void FakeCompositorFrameSinkClient::SetBeginFrameSource(
+    BeginFrameSource* source) {
+  begin_frame_source_ = source;
+}
+
 void FakeCompositorFrameSinkClient::DidReceiveCompositorFrameAck() {
   ack_count_++;
 }
 
 void FakeCompositorFrameSinkClient::DidLoseCompositorFrameSink() {
   did_lose_compositor_frame_sink_called_ = true;
 }
 
 void FakeCompositorFrameSinkClient::SetMemoryPolicy(
     const ManagedMemoryPolicy& policy) {
   memory_policy_ = policy;
 }
 
 }  // namespace cc