Add cricket::VideoFrame::frame_id() and set it to RTP timestamp.

webrtc/sdk/objc/Framework/Classes/avfoundationvideocapturer.mm

 /*
  *  Copyright 2015 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 700 matching lines @@
       adapted_height != captured_height || crop_height != captured_height) {
     // TODO(magjed): Avoid converting to I420.
     rtc::scoped_refptr<webrtc::I420Buffer> scaled_buffer(
         _buffer_pool.CreateBuffer(adapted_width, adapted_height));
     scaled_buffer->CropAndScaleFrom(buffer->NativeToI420Buffer(), crop_x,
                                     crop_y, crop_width, crop_height);
     buffer = scaled_buffer;
   }
 
   OnFrame(cricket::WebRtcVideoFrame(buffer, webrtc::kVideoRotation_0,
-                                    translated_camera_time_us),
+                                    translated_camera_time_us, 0),
           captured_width, captured_height);
 
   CVBufferRelease(image_buffer);
 }
 
 }  // namespace webrtc