[Mojo Video Capture] Retire buffers when Android Chromium goes to the background

services/video_capture/receiver_mojo_to_media_adapter.cc

 // Copyright 2016 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 "services/video_capture/receiver_mojo_to_media_adapter.h"
 
 #include "media/mojo/common/media_type_converters.h"
 #include "media/mojo/common/mojo_shared_buffer_video_frame.h"
 
 namespace video_capture {
@@ skipping 11 matching lines @@
 }
 
 void ReceiverMojoToMediaAdapter::OnError() {
   receiver_->OnError();
 }
 
 void ReceiverMojoToMediaAdapter::OnLog(const std::string& message) {
   receiver_->OnLog(message);
 }
 
-void ReceiverMojoToMediaAdapter::OnBufferDestroyed(int buffer_id_to_drop) {
-  // Nothing to do here.
-  // This call is only needed for clients who need to explicitly share buffers
-  // with other processes and keep track of which buffers the buffer pool is
-  // no longer going to reuse/resurrect.
-  // In the world of Mojo, we do not need to share buffers explicitly.
+void ReceiverMojoToMediaAdapter::OnBufferRetired(int buffer_id) {
+  NOTIMPLEMENTED();
 }
 
 }  // namespace video_capture