Remove GetVolume from media::AudioRendererSink.

content/renderer/media/render_audiosourceprovider.cc

Index: content/renderer/media/render_audiosourceprovider.cc
diff --git a/content/renderer/media/render_audiosourceprovider.cc b/content/renderer/media/render_audiosourceprovider.cc
index 039f75fb8f8c96dc3f01edf30ae50add4b65ebc3..c0a05806dc3923e09cebdf6fe9789df7abdf7a41 100644
--- a/content/renderer/media/render_audiosourceprovider.cc
+++ b/content/renderer/media/render_audiosourceprovider.cc
@@ -18,7 +18,6 @@ RenderAudioSourceProvider::RenderAudioSourceProvider()
       channels_(0),
       sample_rate_(0),
       is_running_(false),
-      volume_(1.0),
       renderer_(NULL),
       client_(NULL) {
   // We create the AudioDevice here using the factory. But we don't yet know
@@ -114,17 +113,9 @@ bool RenderAudioSourceProvider::SetVolume(double volume) {
   base::AutoLock auto_lock(sink_lock_);
   if (!client_)
     default_sink_->SetVolume(volume);
-  volume_ = volume;
   return true;
 }
 
-void RenderAudioSourceProvider::GetVolume(double* volume) {
-  if (!client_)
-    default_sink_->GetVolume(volume);
-  else if (volume)
-    *volume = volume_;
-}
-
 void RenderAudioSourceProvider::Initialize(
     const media::AudioParameters& params,
     RenderCallback* renderer) {