Reland of Switch to use SequencedTaskChecker instead of ThreadChecker where needed.

webrtc/modules/video_coding/video_coding_impl.h

 /*
  *  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.
  */
 
 #ifndef WEBRTC_MODULES_VIDEO_CODING_VIDEO_CODING_IMPL_H_
 #define WEBRTC_MODULES_VIDEO_CODING_VIDEO_CODING_IMPL_H_
 
 #include "webrtc/modules/video_coding/include/video_coding.h"
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "webrtc/base/onetimeevent.h"
 #include "webrtc/base/thread_annotations.h"
-#include "webrtc/base/thread_checker.h"
+#include "webrtc/base/sequenced_task_checker.h"
 #include "webrtc/common_video/include/frame_callback.h"
 #include "webrtc/modules/video_coding/codec_database.h"
 #include "webrtc/modules/video_coding/frame_buffer.h"
 #include "webrtc/modules/video_coding/generic_decoder.h"
 #include "webrtc/modules/video_coding/generic_encoder.h"
 #include "webrtc/modules/video_coding/jitter_buffer.h"
 #include "webrtc/modules/video_coding/media_optimization.h"
 #include "webrtc/modules/video_coding/receiver.h"
 #include "webrtc/modules/video_coding/timing.h"
 #include "webrtc/modules/video_coding/utility/qp_parser.h"
@@ skipping 68 matching lines @@
   VCMGenericEncoder* _encoder;
   media_optimization::MediaOptimization _mediaOpt;
   VCMEncodedFrameCallback _encodedFrameCallback GUARDED_BY(encoder_crit_);
   VCMSendStatisticsCallback* const send_stats_callback_;
   VCMCodecDataBase _codecDataBase GUARDED_BY(encoder_crit_);
   bool frame_dropper_enabled_ GUARDED_BY(encoder_crit_);
   VCMProcessTimer _sendStatsTimer;
 
   // Must be accessed on the construction thread of VideoSender.
   VideoCodec current_codec_;
-  rtc::ThreadChecker main_thread_;
-
+  rtc::SequencedTaskChecker sequenced_checker_;
 
   rtc::CriticalSection params_crit_;
   EncoderParameters encoder_params_ GUARDED_BY(params_crit_);
   bool encoder_has_internal_source_ GUARDED_BY(params_crit_);
   std::string encoder_name_ GUARDED_BY(params_crit_);
   std::vector<FrameType> next_frame_types_ GUARDED_BY(params_crit_);
 };
 
 class VideoReceiver : public Module {
  public:
@@ skipping 80 matching lines @@
   VCMProcessTimer _receiveStatsTimer;
   VCMProcessTimer _retransmissionTimer;
   VCMProcessTimer _keyRequestTimer;
   QpParser qp_parser_;
   ThreadUnsafeOneTimeEvent first_frame_received_;
 };
 
 }  // namespace vcm
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_VIDEO_CODING_VIDEO_CODING_IMPL_H_