Android video capture: only use reference time for outbound timestamp.

media/capture/video/android/video_capture_device_android.cc

Index: media/capture/video/android/video_capture_device_android.cc
diff --git a/media/capture/video/android/video_capture_device_android.cc b/media/capture/video/android/video_capture_device_android.cc
index b56fc7452502aa9ee0d9055bf6e918f9ebfa86c9..58e7202effb827510401cc0c188ca0c3a81512a3 100644
--- a/media/capture/video/android/video_capture_device_android.cc
+++ b/media/capture/video/android/video_capture_device_android.cc
@@ -252,7 +252,6 @@ void VideoCaptureDeviceAndroid::OnFrameAvailable(
     if (!got_first_frame_) {
       // Set aside one frame allowance for fluctuation.
       expected_next_frame_time_ = current_time - frame_interval_;
-      first_ref_time_ = current_time;
       got_first_frame_ = true;
 
       for (const auto& request : photo_requests_queue_)
@@ -272,7 +271,7 @@ void VideoCaptureDeviceAndroid::OnFrameAvailable(
       return;
     client_->OnIncomingCapturedData(reinterpret_cast<uint8_t*>(buffer), length,
                                     capture_format_, rotation, current_time,
-                                    current_time - first_ref_time_);
+                                    base::TimeDelta());

[miu, 2016/09/02 21:49:15]

I'm pretty sure this could throw off consumers of the video frames downstream.
You should try your best to provide reasonable media timestamp values here.

Perhaps revert this to use "current_time - first_ref_time_" like it was before?

[braveyao, 2016/09/02 23:25:53]

Done.

   }
 
   env->ReleaseByteArrayElements(data, buffer, JNI_ABORT);
@@ -288,12 +287,17 @@ void VideoCaptureDeviceAndroid::OnI420FrameAvailable(JNIEnv* env,
                                                      jint uv_pixel_stride,
                                                      jint width,
                                                      jint height,
-                                                     jint rotation) {
+                                                     jint rotation,
+                                                     jlong timestamp) {
   {
     base::AutoLock lock(lock_);
     if (state_ != kConfigured || !client_)
       return;
   }
+  const int64_t absolute_micro =
+      timestamp / base::Time::kNanosecondsPerMicrosecond;
+  const base::TimeDelta capture_time =
+      base::TimeDelta::FromMicroseconds(absolute_micro);
 
   const base::TimeTicks current_time = base::TimeTicks::Now();
   {
@@ -301,7 +305,6 @@ void VideoCaptureDeviceAndroid::OnI420FrameAvailable(JNIEnv* env,
     if (!got_first_frame_) {
       // Set aside one frame allowance for fluctuation.
       expected_next_frame_time_ = current_time - frame_interval_;
-      first_ref_time_ = current_time;
       got_first_frame_ = true;
 
       for (const auto& request : photo_requests_queue_)
@@ -342,7 +345,7 @@ void VideoCaptureDeviceAndroid::OnI420FrameAvailable(JNIEnv* env,
       return;
     client_->OnIncomingCapturedData(buffer.get(), buffer_length,
                                     capture_format_, rotation, current_time,
-                                    current_time - first_ref_time_);
+                                    capture_time);
   }
 }