Ignore inter-frame delay stats samples when stream is inactive

webrtc/video/receive_statistics_proxy.h

Index: webrtc/video/receive_statistics_proxy.h
diff --git a/webrtc/video/receive_statistics_proxy.h b/webrtc/video/receive_statistics_proxy.h
index 8aff1a254c47ec6c79f50696cb13009350822d98..cd5c9026800c6acd339360f35085fb9f4113b427 100644
--- a/webrtc/video/receive_statistics_proxy.h
+++ b/webrtc/video/receive_statistics_proxy.h
@@ -58,6 +58,9 @@ class ReceiveStatisticsProxy : public VCMReceiveStatisticsCallback,
   void OnPreDecode(const EncodedImage& encoded_image,
                    const CodecSpecificInfo* codec_specific_info);
 
+  // Indicates video stream has been paused (no incoming packets).
+  void OnStreamInactive();
+
   // Overrides VCMReceiveStatisticsCallback.
   void OnReceiveRatesUpdated(uint32_t bitRate, uint32_t frameRate) override;
   void OnFrameCountsUpdated(const FrameCounts& frame_counts) override;
@@ -160,7 +163,7 @@ class ReceiveStatisticsProxy : public VCMReceiveStatisticsCallback,
   int64_t avg_rtt_ms_ GUARDED_BY(crit_);
   mutable std::map<int64_t, size_t> frame_window_ GUARDED_BY(&crit_);
   VideoContentType last_content_type_ GUARDED_BY(&crit_);
-  rtc::Optional<int64_t> last_decoded_frame_time_ms_;
+  rtc::Optional<int64_t> last_decoded_frame_time_ms_ GUARDED_BY(&crit_);
   rtc::Optional<TimingFrameInfo> timing_frame_info_ GUARDED_BY(&crit_);
 };