cast: Support for low-latency interactive mode

media/capture/content/video_capture_oracle.cc

Index: media/capture/content/video_capture_oracle.cc
diff --git a/media/capture/content/video_capture_oracle.cc b/media/capture/content/video_capture_oracle.cc
index 461200d41d58ee65f372378637a4f67ea3c15b51..fbed1e927407610e3677c8dba36f3864e9326b2a 100644
--- a/media/capture/content/video_capture_oracle.cc
+++ b/media/capture/content/video_capture_oracle.cc
@@ -303,6 +303,12 @@ bool VideoCaptureOracle::CompleteCapture(int frame_number,
   return true;
 }
 
+bool VideoCaptureOracle::IsAnimationActive() const {
+  base::TimeDelta duration =
+      base::TimeTicks::Now() - last_time_animation_was_detected_;
+  return duration.InMicroseconds() < kDebouncingPeriodForAnimatedContentMicros;

[miu, 2015/12/01 21:15:27]

I don't think this does what you intended.  The kDebouncingPeriod is something
orthogonal.  It was meant to prevent unintended resolution increases as the
"capability" signals fluctuate.

The VCOracle only sets |last_time_animation_was_detected_| after the
AnimatedContentSampler detects animation, and that takes 1-2 seconds' worth of
events to trigger.  So, I think you can just use that.

Overall, I suggest an inline accessor for |last_time_animation_was_detected_|
and plumb this timestamp through to video_sender.cc.

[Irfan, 2015/12/02 22:32:44]

As discussed, this has the same intention. Will be moving the logic out though.

+}
+
 void VideoCaptureOracle::RecordConsumerFeedback(int frame_number,
                                                 double resource_utilization) {
   if (!auto_throttling_enabled_)