Fix the video buffer size should take rtt into consideration

webrtc/modules/video_coding/frame_buffer2.h

Index: webrtc/modules/video_coding/frame_buffer2.h
diff --git a/webrtc/modules/video_coding/frame_buffer2.h b/webrtc/modules/video_coding/frame_buffer2.h
index 307bb85b46c339d7121d0f5ea4187a9f7897d727..4950dac3ffa7bf08e8fdb73b506f2cc675ab3d0a 100644
--- a/webrtc/modules/video_coding/frame_buffer2.h
+++ b/webrtc/modules/video_coding/frame_buffer2.h
@@ -73,6 +73,9 @@ class FrameBuffer {
   // return immediately.
   void Stop();
 
+  // Updates the RTT for jitter buffer estimation.
+  void UpdateRtt(int64_t rtt_ms);
+
  private:
   struct FrameKey {
     FrameKey() : picture_id(0), spatial_layer(0) {}