Report video and network stats averaged over 1s, and create corresponding UMA metrics.

remoting/client/plugin/pepper_video_renderer_3d.cc

Index: remoting/client/plugin/pepper_video_renderer_3d.cc
diff --git a/remoting/client/plugin/pepper_video_renderer_3d.cc b/remoting/client/plugin/pepper_video_renderer_3d.cc
index 711c2104b702cf083f78a4b4b337286fb20eb91e..3bf5619dbbeb39faca331dfec65dae6390c70b79 100644
--- a/remoting/client/plugin/pepper_video_renderer_3d.cc
+++ b/remoting/client/plugin/pepper_video_renderer_3d.cc
@@ -189,14 +189,18 @@ void PepperVideoRenderer3D::ProcessVideoPacket(scoped_ptr<VideoPacket> packet,
                                                const base::Closure& done) {
   base::ScopedClosureRunner done_runner(done);
 
+  stats_.video_fps_with_empty_frames()->Record(1);
   // Don't need to do anything if the packet is empty. Host sends empty video
   // packets when the screen is not changing.
-  if (!packet->data().size())
+  if (!packet->data().size()) {
     return;
+  }
 
   // Update statistics.
   stats_.video_frame_rate()->Record(1);
+  stats_.video_fps()->Record(1);
   stats_.video_bandwidth()->Record(packet->data().size());
+  stats_.video_bytes_per_s()->Record(packet->data().size());

[Wez, 2015/06/29 14:56:13]

This ends up being pretty ugly.

Could we instead switch all the plugin-side sampling to per-second and build the
longer-term averaging into the app, for example? Would need some care to make
sure the difference in calculations didn't lead to output incomparable with
older stats.

[anandc, 2015/06/30 20:17:39]

Agreed. 
If we use only the per-second sampling, the stats shown in the web-app will only
report FPS, etc for the last second every 60s. This might be acceptable, but
might also make sudden ups/downs more prominent, depending on  timing.
Other than that, I don't think there are other places where the default 3s
window metrics are used.
sergeyu@ might know more about any other implications of removing the 3s window
metrics.

In the meantime, I've updated the metrics names to hopefully make their
different intents more obvious and make this a little less ugly.

   if (packet->has_capture_time_ms())
     stats_.video_capture_ms()->Record(packet->capture_time_ms());
   if (packet->has_encode_time_ms())