Remove unused flush operation from Chromium audio.

content/browser/renderer_host/media/audio_renderer_host.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // AudioRendererHost serves audio related requests from AudioRenderer which
 // lives inside the render process and provide access to audio hardware.
 //
 // This class is owned by BrowserRenderProcessHost, and instantiated on UI
 // thread, but all other operations and method calls happen on IO thread, so we
 // need to be extra careful about the lifetime of this object. AudioManager is a
@@ skipping 91 matching lines @@
   // Track that the data for the audio stream referenced by |stream_id| is
   // produced by an entity in the render view referenced by |render_view_id|.
   void OnAssociateStreamWithProducer(int stream_id, int render_view_id);
 
   // Play the audio stream referenced by |stream_id|.
   void OnPlayStream(int stream_id);
 
   // Pause the audio stream referenced by |stream_id|.
   void OnPauseStream(int stream_id);
 
-  // Discard all audio data in stream referenced by |stream_id|.
-  void OnFlushStream(int stream_id);
-
   // Close the audio stream referenced by |stream_id|.
   void OnCloseStream(int stream_id);
 
   // Set the volume of the audio stream referenced by |stream_id|.
   void OnSetVolume(int stream_id, double volume);
 
   // Complete the process of creating an audio stream. This will set up the
   // shared memory or shared socket in low latency mode.
   void DoCompleteCreation(AudioEntry* entry);
 
@@ skipping 23 matching lines @@
 
   // A map of stream IDs to audio sources.
   AudioEntryMap audio_entries_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioRendererHost);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_RENDERER_HOST_H_