Remove unused flush operation from Chromium audio.

content/browser/renderer_host/media/audio_renderer_host.cc

Index: content/browser/renderer_host/media/audio_renderer_host.cc
diff --git a/content/browser/renderer_host/media/audio_renderer_host.cc b/content/browser/renderer_host/media/audio_renderer_host.cc
index 2aee887d67e1081ffeffc4e591e1e9ebec8d0650..7312f8de604a0d54dd098341467ce6c21024a60b 100644
--- a/content/browser/renderer_host/media/audio_renderer_host.cc
+++ b/content/browser/renderer_host/media/audio_renderer_host.cc
@@ -261,7 +261,6 @@ bool AudioRendererHost::OnMessageReceived(const IPC::Message& message,
                         OnAssociateStreamWithProducer)
     IPC_MESSAGE_HANDLER(AudioHostMsg_PlayStream, OnPlayStream)
     IPC_MESSAGE_HANDLER(AudioHostMsg_PauseStream, OnPauseStream)
-    IPC_MESSAGE_HANDLER(AudioHostMsg_FlushStream, OnFlushStream)
     IPC_MESSAGE_HANDLER(AudioHostMsg_CloseStream, OnCloseStream)
     IPC_MESSAGE_HANDLER(AudioHostMsg_SetVolume, OnSetVolume)
     IPC_MESSAGE_UNHANDLED(handled = false)
@@ -374,20 +373,6 @@ void AudioRendererHost::OnPauseStream(int stream_id) {
     media_internals_->OnSetAudioStreamPlaying(this, stream_id, false);
 }
 
-void AudioRendererHost::OnFlushStream(int stream_id) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-
-  AudioEntry* entry = LookupById(stream_id);
-  if (!entry) {
-    SendErrorMessage(stream_id);
-    return;
-  }
-
-  entry->controller()->Flush();
-  if (media_internals_)
-    media_internals_->OnSetAudioStreamStatus(this, stream_id, "flushed");
-}
-
 void AudioRendererHost::OnSetVolume(int stream_id, double volume) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));