android: Don't do a thread jump for incoming frames.

webrtc/media/base/videobroadcaster.cc

 /*
  *  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 22 matching lines @@
 void VideoBroadcaster::RemoveSink(
     VideoSinkInterface<cricket::VideoFrame>* sink) {
   RTC_DCHECK(thread_checker_.CalledOnValidThread());
   RTC_DCHECK(sink != nullptr);
   rtc::CritScope cs(&sinks_and_wants_lock_);
   VideoSourceBase::RemoveSink(sink);
   UpdateWants();
 }
 
 bool VideoBroadcaster::frame_wanted() const {
-  RTC_DCHECK(thread_checker_.CalledOnValidThread());
   rtc::CritScope cs(&sinks_and_wants_lock_);
   return !sink_pairs().empty();
 }
 
 VideoSinkWants VideoBroadcaster::wants() const {
   RTC_DCHECK(thread_checker_.CalledOnValidThread());
   rtc::CritScope cs(&sinks_and_wants_lock_);
   return current_wants_;
 }
 
@@ skipping 50 matching lines @@
   }
   black_frame_.reset(new cricket::WebRtcVideoFrame(
       new rtc::RefCountedObject<webrtc::I420Buffer>(frame.width(),
                                                     frame.height()),
       frame.rotation(), frame.timestamp_us()));
   black_frame_->SetToBlack();
   return *black_frame_;
 }
 
 }  // namespace rtc