Add a method to tab_utils.h to find out whether a tab is playing audio.

chrome/browser/ui/tabs/tab_utils.cc

 // 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.
 
 #include "chrome/browser/ui/tabs/tab_utils.h"
 
+#include "chrome/browser/media/audio_stream_indicator.h"
 #include "chrome/browser/media/media_internals.h"
 #include "chrome/browser/media/media_stream_capture_indicator.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/web_contents.h"
 
 namespace chrome {
 
 bool ShouldShowProjectingIndicator(content::WebContents* contents) {
   int render_process_id = contents->GetRenderProcessHost()->GetID();
@@ skipping 11 matching lines @@
       MediaInternals::GetInstance()->GetMediaStreamCaptureIndicator();
   // The projecting indicator takes precedence over the recording indicator, but
   // if we are projecting and we don't handle the projecting case we want to
   // still show the recording indicator.
   return capture_indicator->IsProcessCapturing(render_process_id,
                                                render_view_id) ||
          capture_indicator->IsProcessCapturingTab(render_process_id,
                                                   render_view_id);
 }
 
+bool ShouldShowAudioIndicator(content::WebContents* contents) {
+  AudioStreamIndicator* audio_indicator =
+      MediaInternals::GetInstance()->GetAudioStreamIndicator();
+  return audio_indicator->IsPlayingAudio(contents);
+}
+
 }  // namespace chrome