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

webrtc/api/androidvideotracksource.cc

Index: webrtc/api/androidvideotracksource.cc
diff --git a/webrtc/api/androidvideotracksource.cc b/webrtc/api/androidvideotracksource.cc
index c52e4f84ff6e3bdeb66d7aea12022a8ea715dd75..80e7894a4b77571dd327123c29e9829a759f237d 100644
--- a/webrtc/api/androidvideotracksource.cc
+++ b/webrtc/api/androidvideotracksource.cc
@@ -146,7 +146,7 @@ void AndroidVideoTrackSource::OnByteBufferFrameCaptured(const void* frame_data,
               buffer,
               apply_rotation_ ? webrtc::kVideoRotation_0
                               : static_cast<webrtc::VideoRotation>(rotation),
-              translated_camera_time_us),
+              translated_camera_time_us, 0),
           width, height);
 }
 
@@ -197,7 +197,7 @@ void AndroidVideoTrackSource::OnTextureFrameCaptured(
                   webrtc_jni::NativeHandleImpl(handle.oes_texture_id, matrix)),
               apply_rotation_ ? webrtc::kVideoRotation_0
                               : static_cast<webrtc::VideoRotation>(rotation),
-              translated_camera_time_us),
+              translated_camera_time_us, 0),
           width, height);
 }