Adds time measurement of WebRtcAudioRenderer::Render

media/audio/audio_output_device.cc

Index: media/audio/audio_output_device.cc
diff --git a/media/audio/audio_output_device.cc b/media/audio/audio_output_device.cc
index 5cc602197eb57c7ee57ae6684d105703078e2bfb..cb78ccbfee82cf2dced25f2c11c21b3403d98b10 100644
--- a/media/audio/audio_output_device.cc
+++ b/media/audio/audio_output_device.cc
@@ -10,6 +10,7 @@
 #include "base/time/time.h"
 #include "media/audio/audio_output_controller.h"
 #include "media/base/limits.h"
+#include "media/base/scoped_histogram_timer.h"
 
 namespace media {
 
@@ -290,6 +291,8 @@ void AudioOutputDevice::AudioThreadCallback::Process(int pending_data) {
   if (pending_data < 0)
     return;
 
+  SCOPED_UMA_HISTOGRAM_TIMER("Media.AudioOutputDevice.ProcessTime");

[no longer working on chromium, 2014/09/17 14:54:50]

I would suggest moving the code to webrtc_audio_renderer.cc, and how about
logging it every 10 callbacks (every 100ms)?

[henrika (OOO until Aug 14), 2014/09/18 10:56:47]

I could move it but AFAIK it is not possible to log at a lower frequency due to
the design of SCOPED_UMA_HISTOGRAM_TIMER. It will only measure the elapsed time
int scope and I can't figure out a way to do so and at the same time check a
counter. If so, I would have to add my time measurement manually instead.

[henrika (OOO until Aug 14), 2014/09/18 11:03:16]

Let me see if I can do something without the macro instead.

+
   // Convert the number of pending bytes in the render buffer into milliseconds.
   int audio_delay_milliseconds = pending_data / bytes_per_ms_;