Express audio delay more precisely in frames rather than milliseconds.

media/base/audio_renderer_mixer.cc

Index: media/base/audio_renderer_mixer.cc
diff --git a/media/base/audio_renderer_mixer.cc b/media/base/audio_renderer_mixer.cc
index 218bb9e2c560de40398bf3696195905bbfcee365..f4240e5500e6b8bb6c64ad06cf83194c72a42e07 100644
--- a/media/base/audio_renderer_mixer.cc
+++ b/media/base/audio_renderer_mixer.cc
@@ -17,6 +17,9 @@ AudioRendererMixer::AudioRendererMixer(
     const scoped_refptr<AudioRendererSink>& sink)
     : audio_sink_(sink),
       output_params_(output_params),
+      microseconds_per_frame_(

[DaleCurtis, 2016/02/11 01:57:15]

Should we instead have a AudioParameters::GetMicrosecondsPerSecond() call which
returns a double? Seems there might be quite a few call sites.

[chcunningham, 2016/02/11 21:02:52]

Done.

+          static_cast<double>(base::Time::kMicrosecondsPerSecond) /
+          output_params.sample_rate()),
       master_converter_(output_params, output_params, true),
       pause_delay_(base::TimeDelta::FromSeconds(kPauseDelaySeconds)),
       last_play_time_(base::TimeTicks::Now()),
@@ -117,7 +120,7 @@ OutputDevice* AudioRendererMixer::GetOutputDevice() {
 }
 
 int AudioRendererMixer::Render(AudioBus* audio_bus,
-                               uint32_t audio_delay_milliseconds,
+                               uint32_t frames_delayed,
                                uint32_t frames_skipped) {
   base::AutoLock auto_lock(lock_);
 
@@ -132,8 +135,10 @@ int AudioRendererMixer::Render(AudioBus* audio_bus,
     playing_ = false;
   }
 
-  master_converter_.ConvertWithDelay(
-      base::TimeDelta::FromMilliseconds(audio_delay_milliseconds), audio_bus);
+  base::TimeDelta audio_delay = base::TimeDelta::FromMicroseconds(
+      frames_delayed * microseconds_per_frame_);
+

[DaleCurtis, 2016/02/11 01:57:15]

Mark as TODO: Remove conversion once AudioConverter supports frames instead of
TimeDelta?

[chcunningham, 2016/02/11 21:02:52]

Done.

+  master_converter_.ConvertWithDelay(audio_delay, audio_bus);
   return audio_bus->frames();
 }