Implement timing frames.

webrtc/video/vie_encoder.cc

Index: webrtc/video/vie_encoder.cc
diff --git a/webrtc/video/vie_encoder.cc b/webrtc/video/vie_encoder.cc
index 203d1c405a8813d05b627cd464803bb9df39f645..57d8c2ff1b02f6b9c8433e877fcce5155c5bea35 100644
--- a/webrtc/video/vie_encoder.cc
+++ b/webrtc/video/vie_encoder.cc
@@ -581,7 +581,13 @@ void ViEEncoder::OnFrame(const VideoFrame& video_frame) {
   VideoFrame incoming_frame = video_frame;
 
   // Local time in webrtc time base.
-  int64_t current_time_ms = clock_->TimeInMilliseconds();
+  int64_t current_time_us = clock_->TimeInMicroseconds();
+  int64_t current_time_ms = current_time_us / rtc::kNumMicrosecsPerMillisec;
+  // If the frame is not from the capturer but from decoder, render time may
+  // be set to the future. To avoid irregularities in statistics, where frame
+  // is captured after being encoded, we should reset capture time here.
+  if (incoming_frame.timestamp_us() > current_time_us)
+    incoming_frame.set_timestamp_us(current_time_us);
 
   // Capture time may come from clock with an offset and drift from clock_.
   int64_t capture_ntp_time_ms;