Updates to VCMDecodedFrameCallback, VideoReceiver and a few related classes/tests.

webrtc/video/video_receive_stream.cc

Index: webrtc/video/video_receive_stream.cc
diff --git a/webrtc/video/video_receive_stream.cc b/webrtc/video/video_receive_stream.cc
index be623cef56ade6bd4c3f60357bdc7eb47db151ad..2b0a5d10fe67e4aa358baa6e2e50819e2d3698e5 100644
--- a/webrtc/video/video_receive_stream.cc
+++ b/webrtc/video/video_receive_stream.cc
@@ -488,8 +488,10 @@ bool VideoReceiveStream::Decode() {
   video_coding::FrameBuffer::ReturnReason res =
       frame_buffer_->NextFrame(kMaxWaitForFrameMs, &frame);
 
-  if (res == video_coding::FrameBuffer::ReturnReason::kStopped)
+  if (res == video_coding::FrameBuffer::ReturnReason::kStopped) {
+    video_receiver_.DecodingStopped();
     return false;
+  }
 
   if (frame) {
     if (video_receiver_.Decode(frame.get()) == VCM_OK)