RtcVideoEncoder: use the timestamp from encoder.

content/renderer/media/rtc_video_encoder.cc

Index: content/renderer/media/rtc_video_encoder.cc
diff --git a/content/renderer/media/rtc_video_encoder.cc b/content/renderer/media/rtc_video_encoder.cc
index cb7752ba848c66bb1f0957f2e07e7267341824c0..3e93017540e44b269ea049a584352b8e6d74346d 100644
--- a/content/renderer/media/rtc_video_encoder.cc
+++ b/content/renderer/media/rtc_video_encoder.cc
@@ -473,17 +473,21 @@ void RTCVideoEncoder::Impl::BitstreamBufferReady(int32_t bitstream_buffer_id,
   }
   output_buffers_free_count_--;
 
-  // CrOS Nyan provides invalid timestamp. Use the current time for now.
-  // TODO(wuchengli): use the timestamp in BitstreamBufferReady after Nyan is
-  // fixed. http://crbug.com/620565.
-  const int64_t capture_time_us = rtc::TimeMicros();
-
   // Derive the capture time (in ms) and RTP timestamp (in 90KHz ticks).
-  const int64_t capture_time_ms =
-      capture_time_us / base::Time::kMicrosecondsPerMillisecond;
+  int64_t capture_time_ms;
+  uint32_t rtp_timestamp;
 
-  const uint32_t rtp_timestamp = static_cast<uint32_t>(
+  if (!timestamp.is_zero()) {
+    capture_time_ms = timestamp.InMilliseconds();
+    rtp_timestamp = static_cast<uint32_t>(timestamp.InMilliseconds()) * 90;
+  } else {
+    // Fallback to the current time if encoder does not provide timestamp.
+    const int64_t capture_time_us = rtc::TimeMicros();
+    capture_time_ms =
+        capture_time_us / base::Time::kMicrosecondsPerMillisecond;
+    rtp_timestamp = static_cast<uint32_t>(
       capture_time_us * 90 / base::Time::kMicrosecondsPerMillisecond);
+  }
 
   webrtc::EncodedImage image(
       reinterpret_cast<uint8_t*>(output_buffer->memory()), payload_size,
@@ -567,13 +571,18 @@ void RTCVideoEncoder::Impl::EncodeOneFrame() {
   }
 
   if (requires_copy) {
+    base::TimeDelta timestamp;

[shenghao1, 2016/06/29 08:39:17]

Consider to change to:
base::TimeDelta timestamp = frame ? frame->timestamp() :
base::TimeDelta::FromMilliseconds(next_frame->ntp_time_ms());

[wuchengli, 2016/06/29 08:48:42]

Done. I also ran git cl format.

+    if (frame)
+      timestamp = frame->timestamp();
+    else
+      timestamp = base::TimeDelta::FromMilliseconds(next_frame->ntp_time_ms());
     base::SharedMemory* input_buffer = input_buffers_[index];
     frame = media::VideoFrame::WrapExternalSharedMemory(
         media::PIXEL_FORMAT_I420, input_frame_coded_size_,
         gfx::Rect(input_visible_size_), input_visible_size_,
         reinterpret_cast<uint8_t*>(input_buffer->memory()),
         input_buffer->mapped_size(), input_buffer->handle(), 0,
-        base::TimeDelta::FromMilliseconds(next_frame->ntp_time_ms()));
+        timestamp);
     if (!frame.get()) {
       LogAndNotifyError(FROM_HERE, "failed to create frame",
                         media::VideoEncodeAccelerator::kPlatformFailureError);