Set capture_time_ms using rtc::TimeMicros()

content/renderer/media/gpu/rtc_video_encoder.cc

Index: content/renderer/media/gpu/rtc_video_encoder.cc
diff --git a/content/renderer/media/gpu/rtc_video_encoder.cc b/content/renderer/media/gpu/rtc_video_encoder.cc
index 4c42938e2a4bef07048703ba1fb759c6d4448135..db6eaa669ac77aa20fa6faf2ff265f2fd06b4c67 100644
--- a/content/renderer/media/gpu/rtc_video_encoder.cc
+++ b/content/renderer/media/gpu/rtc_video_encoder.cc
@@ -470,16 +470,13 @@ void RTCVideoEncoder::Impl::BitstreamBufferReady(int32_t bitstream_buffer_id,
   output_buffers_free_count_--;
 

[nisse-chromium (ooo August 14), 2017/02/15 07:53:18]

I'd suggest reading system clock up front,

int64_t current_time_us = rtc::TimeMicros();

and then use this value both for the fallback and for setting
image.capture_time. 

[Stefan, 2017/02/15 12:31:24]

You should then also make sure that two frames don't get the same timestamp
(make sure there's at least 1 ms difference or similar). Two frames with equal
timestamps can confuse the RTP layers.

[emircan, 2017/02/15 19:35:34]

Done.

[emircan, 2017/02/15 19:35:34]

Done.

   // Derive the capture time (in ms) and RTP timestamp (in 90KHz ticks).
-  int64_t capture_time_us, capture_time_ms;
+  int64_t capture_time_us;
   uint32_t rtp_timestamp;
-
   if (!timestamp.is_zero()) {
-    capture_time_us = timestamp.InMicroseconds();;
-    capture_time_ms = timestamp.InMilliseconds();
+    capture_time_us = timestamp.InMicroseconds();
   } else {
     // Fallback to the current time if encoder does not provide timestamp.
     capture_time_us = rtc::TimeMicros();
-    capture_time_ms = capture_time_us / base::Time::kMicrosecondsPerMillisecond;
   }
   // RTP timestamp can wrap around. Get the lower 32 bits.
   rtp_timestamp = static_cast<uint32_t>(
@@ -491,7 +488,9 @@ void RTCVideoEncoder::Impl::BitstreamBufferReady(int32_t bitstream_buffer_id,
   image._encodedWidth = input_visible_size_.width();
   image._encodedHeight = input_visible_size_.height();
   image._timeStamp = rtp_timestamp;
-  image.capture_time_ms_ = capture_time_ms;
+  // This should be always based on system clock, so leave setting this field to
+  // rtp code.
+  image.capture_time_ms_ = -1;
   image._frameType =
       (key_frame ? webrtc::kVideoFrameKey : webrtc::kVideoFrameDelta);
   image._completeFrame = true;