Change FrameBuffer::Stop to not require a critical section.

webrtc/modules/video_coding/frame_buffer2.h

 /*
  *  Copyright (c) 2016 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 131 matching lines @@
       EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
   void UpdateJitterDelay() EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
   void ClearFramesAndHistory() EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
   FrameMap frames_ GUARDED_BY(crit_);
 
   rtc::CriticalSection crit_;
   Clock* const clock_;
-  rtc::Event new_countinuous_frame_event_;
+  rtc::Event new_continuous_frame_event_;
   VCMJitterEstimator* const jitter_estimator_ GUARDED_BY(crit_);
   VCMTiming* const timing_ GUARDED_BY(crit_);
   VCMInterFrameDelay inter_frame_delay_ GUARDED_BY(crit_);
   uint32_t last_decoded_frame_timestamp_ GUARDED_BY(crit_);
   FrameMap::iterator last_decoded_frame_it_ GUARDED_BY(crit_);
   FrameMap::iterator last_continuous_frame_it_ GUARDED_BY(crit_);
   FrameMap::iterator next_frame_it_ GUARDED_BY(crit_);
   int num_frames_history_ GUARDED_BY(crit_);
   int num_frames_buffered_ GUARDED_BY(crit_);
-  bool stopped_ GUARDED_BY(crit_);
+  volatile int stopped_;
   VCMVideoProtection protection_mode_ GUARDED_BY(crit_);
   VCMReceiveStatisticsCallback* const stats_callback_;
 
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(FrameBuffer);
 };
 
 }  // namespace video_coding
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_VIDEO_CODING_FRAME_BUFFER2_H_