Bitrate controller for VideoToolbox encoder.

webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_decoder.cc

 /*
  *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  *
  */
@@ skipping 146 matching lines @@
 }
 
 int H264VideoToolboxDecoder::RegisterDecodeCompleteCallback(
     DecodedImageCallback* callback) {
   RTC_DCHECK(!callback_);
   callback_ = callback;
   return WEBRTC_VIDEO_CODEC_OK;
 }
 
 int H264VideoToolboxDecoder::Release() {
+  // Need to invalidate the session so that callbacks no longer occur and it
+  // is safe to null out the callback.
+  DestroyDecompressionSession();
+  SetVideoFormat(nullptr);
   callback_ = nullptr;
   return WEBRTC_VIDEO_CODEC_OK;
 }
 
 int H264VideoToolboxDecoder::ResetDecompressionSession() {
   DestroyDecompressionSession();
 
   // Need to wait for the first SPS to initialize decoder.
   if (!video_format_) {
     return WEBRTC_VIDEO_CODEC_OK;
@@ skipping 79 matching lines @@
   }
 }
 
 const char* H264VideoToolboxDecoder::ImplementationName() const {
   return "VideoToolbox";
 }
 
 }  // namespace webrtc
 
 #endif  // defined(WEBRTC_VIDEO_TOOLBOX_SUPPORTED)