[Chromoting] Send DesktopFrame::capturer_id() to client through WebrtcVideoStream

Once DirectX Capturer is enabled or being experimented, we can use the
capturer_id() logged in clients to analyze the failure rate.

BUG=650926, 679523

Review-Url: https://codereview.chromium.org/2767193007
Cr-Original-Commit-Position: refs/heads/master@{#459625}
Committed: https://chromium.googlesource.com/chromium/src/+/f478d76ee3acd92b6a2cf5ff2e5a0e4094c756db
Review-Url: https://codereview.chromium.org/2767193007
Cr-Commit-Position: refs/heads/master@{#459684}
diff --git a/remoting/protocol/webrtc_video_stream.h b/remoting/protocol/webrtc_video_stream.h
index 6d1d1c67..376eec0 100644
--- a/remoting/protocol/webrtc_video_stream.h
+++ b/remoting/protocol/webrtc_video_stream.h
@@ -52,8 +52,8 @@
   void SetObserver(Observer* observer) override;
 
  private:
-  struct FrameTimestamps;
-  struct EncodedFrameWithTimestamps;
+  struct FrameStats;
+  struct EncodedFrameWithStats;
 
   // webrtc::DesktopCapturer::Callback interface.
   void OnCaptureResult(webrtc::DesktopCapturer::Result result,
@@ -67,12 +67,12 @@
   void CaptureNextFrame();
 
   // Task running on the encoder thread to encode the |frame|.
-  static EncodedFrameWithTimestamps EncodeFrame(
+  static EncodedFrameWithStats EncodeFrame(
       WebrtcVideoEncoder* encoder,
       std::unique_ptr<webrtc::DesktopFrame> frame,
       WebrtcVideoEncoder::FrameParams params,
-      std::unique_ptr<WebrtcVideoStream::FrameTimestamps> timestamps);
-  void OnFrameEncoded(EncodedFrameWithTimestamps frame);
+      std::unique_ptr<WebrtcVideoStream::FrameStats> stats);
+  void OnFrameEncoded(EncodedFrameWithStats frame);
 
   // Capturer used to capture the screen.
   std::unique_ptr<webrtc::DesktopCapturer> capturer_;
@@ -90,8 +90,8 @@
 
   HostVideoStatsDispatcher video_stats_dispatcher_;
 
-  // Timestamps for the frame that's being captured.
-  std::unique_ptr<FrameTimestamps> captured_frame_timestamps_;
+  // Stats of the frame that's being captured.
+  std::unique_ptr<FrameStats> captured_frame_stats_;
 
   std::unique_ptr<WebrtcFrameScheduler> scheduler_;