Add audio signal to the ResourceScheduler.

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 139 matching lines @@
   // AudioOutputController after it has closed.
   void DeleteEntry(scoped_ptr<AudioEntry> entry);
 
   // Send an error message to the renderer, then close the stream.
   void ReportErrorAndClose(int stream_id);
 
   // A helper method to look up a AudioEntry identified by |stream_id|.
   // Returns NULL if not found.
   AudioEntry* LookupById(int stream_id);
 
+  // A helper method to update the number of playing streams and alert the
+  // ResourceScheduler when the renderer starts or stops playing an audiostream.
+  void UpdateNumPlayingStreams(AudioEntry* entry, bool is_playing);
+
+  // Returns true if any streams managed by the RenderView identified by
+  // |render_view_id| are actively playing.
+  bool RenderViewHasActiveAudio(int render_view_id);

[mmenke, 2014/09/19 01:28:57]

nit:  bool RenderViewHasActiveAudio(int render_view_id) const;

+
   // ID of the RenderProcessHost that owns this instance.
   const int render_process_id_;
 
   media::AudioManager* const audio_manager_;
   AudioMirroringManager* const mirroring_manager_;
   scoped_ptr<media::AudioLog> audio_log_;
 
   // Used to access to AudioInputDeviceManager.
   MediaStreamManager* media_stream_manager_;
 
   // A map of stream IDs to audio sources.
   AudioEntryMap audio_entries_;
 
   // The number of streams in the playing state.
   base::AtomicRefCount num_playing_streams_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioRendererHost);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_RENDERER_HOST_H_