Use microsecond timestamp in cricket::VideoFrame.

webrtc/media/base/videocapturer.cc

Index: webrtc/media/base/videocapturer.cc
diff --git a/webrtc/media/base/videocapturer.cc b/webrtc/media/base/videocapturer.cc
index 94f65143531479ab5c9344034a030c8f7edcb501..f9712edd4cb369647695154fe11859b818611952 100644
--- a/webrtc/media/base/videocapturer.cc
+++ b/webrtc/media/base/videocapturer.cc
@@ -224,6 +224,18 @@ void VideoCapturer::OnFrameCaptured(VideoCapturer*,
     return;
   }
 
+  int64_t timestamp_us =

[perkj_webrtc, 2016/04/08 08:22:48]

do this in the frame factory instead. 

[nisse-webrtc, 2016/04/08 09:15:43]

Moving the logic there makes sense, I'll give it a try. Main question is how it
affects chrome's farme factory, but hopefully it has usec timestamps in the
right timescale already.

+      captured_frame->time_stamp / rtc::kNumNanosecsPerMicrosec;
+
+  if (!timestamp_offset_valid_) {
+    timestamp_offset_ = rtc::TimeMicros() - timestamp_us;
+    timestamp_offset_valid_ = true;
+  }
+
+  // Add offset, to get time stamps with the same epoch as the
+  // system monotonic clock, rtc::TimeMicros().
+  timestamp_us += timestamp_offset_;
+
   // Use a temporary buffer to scale
   std::unique_ptr<uint8_t[]> scale_buffer;
   if (IsScreencast()) {
@@ -396,6 +408,11 @@ void VideoCapturer::OnFrameCaptured(VideoCapturer*,
     return;
   }
 
+  // Overrides the timestamp set by the FrameFactory.
+  // TODO(nisse): Arrange to either get the FrameFactory to set the
+  // timestamp with correct offset, or not set the timestamp at all.
+  adapted_frame->set_timestamp_us(timestamp_us);
+
   OnFrame(this, adapted_frame.get());
   UpdateInputSize(captured_frame);
 }