Remove dead RenderThreadImpl::GetAudioHardwareConfig.

content/renderer/render_thread_impl.h

Index: content/renderer/render_thread_impl.h
diff --git a/content/renderer/render_thread_impl.h b/content/renderer/render_thread_impl.h
index bb0553c620455017b2a7aa54c4080c15dea061a7..bae005437a4b5e5f09846ac24747433a424f3614 100644
--- a/content/renderer/render_thread_impl.h
+++ b/content/renderer/render_thread_impl.h
@@ -76,7 +76,6 @@ class MessageFilter;
 }
 
 namespace media {
-class AudioHardwareConfig;
 class GpuVideoAcceleratorFactories;
 }
 
@@ -373,11 +372,6 @@ class CONTENT_EXPORT RenderThreadImpl
   // first call.
   AudioRendererMixerManager* GetAudioRendererMixerManager();
 
-  // AudioHardwareConfig contains audio hardware configuration for
-  // renderer side clients.  Creation requires a synchronous IPC call so it is
-  // lazily created on the first call.
-  media::AudioHardwareConfig* GetAudioHardwareConfig();
-
 #if defined(OS_WIN)
   void PreCacheFontCharacters(const LOGFONT& log_font,
                               const base::string16& str);