Add a race-checking mechanism.

webrtc/common_video/incoming_video_stream.cc

 /*
  *  Copyright (c) 2012 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 31 matching lines @@
     rtc::CritScope cs(&buffer_critsect_);
     render_buffers_.reset();
   }
 
   deliver_buffer_event_->Set();
   incoming_render_thread_.Stop();
   deliver_buffer_event_->StopTimer();
 }
 
 void IncomingVideoStream::OnFrame(const VideoFrame& video_frame) {
-  // Most of the time we'll be on a decoder thread here, but when using
-  // VideoToolbox on iOS, we'll get called on a thread from a thread pool.
-
+  RTC_CHECK_RUNS_SYNCHRONIZED(&decoder_race_checker_);
   // Hand over or insert frame.
   rtc::CritScope csB(&buffer_critsect_);
   if (render_buffers_->AddFrame(video_frame) == 1) {
     deliver_buffer_event_->Set();
   }
 }
 
 bool IncomingVideoStream::IncomingVideoStreamThreadFun(void* obj) {
   return static_cast<IncomingVideoStream*>(obj)->IncomingVideoStreamProcess();
 }
@@ skipping 23 matching lines @@
     deliver_buffer_event_->StartTimer(false, wait_time);
 
     if (frame_to_render) {
       external_callback_->OnFrame(*frame_to_render);
     }
   }
   return true;
 }
 
 }  // namespace webrtc