passing |buffer| by reference in AndroidVideoCapturer::OnIncomingFrame

talk/app/webrtc/androidvideocapturer.cc

 /*
  * libjingle
  * Copyright 2015 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 193 matching lines @@
     return;
   current_state_ = new_state;
 
   // TODO(perkj): SetCaptureState can not be used since it posts to |thread_|.
   // But |thread_ | is currently just the thread that happened to create the
   // cricket::VideoCapturer.
   SignalStateChange(this, new_state);
 }
 
 void AndroidVideoCapturer::OnIncomingFrame(
-    rtc::scoped_refptr<webrtc::VideoFrameBuffer> buffer,
+    const rtc::scoped_refptr<webrtc::VideoFrameBuffer>& buffer,
     int rotation,
     int64_t time_stamp) {
   RTC_CHECK(thread_checker_.CalledOnValidThread());
   frame_factory_->UpdateCapturedFrame(buffer, rotation, time_stamp);
   SignalFrameCaptured(this, frame_factory_->GetCapturedFrame());
   frame_factory_->ClearCapturedFrame();
 }
 
 void AndroidVideoCapturer::OnOutputFormatRequest(
     int width, int height, int fps) {
   RTC_CHECK(thread_checker_.CalledOnValidThread());
   const cricket::VideoFormat& current = video_adapter()->output_format();
   cricket::VideoFormat format(
       width, height, cricket::VideoFormat::FpsToInterval(fps), current.fourcc);
   video_adapter()->OnOutputFormatRequest(format);
 }
 
 bool AndroidVideoCapturer::GetBestCaptureFormat(
     const cricket::VideoFormat& desired,
     cricket::VideoFormat* best_format) {
   // Delegate this choice to VideoCapturerAndroid.startCapture().
   *best_format = desired;
   return true;
 }
 
 }  // namespace webrtc