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

chrome/browser/ui/tabs/tab_utils.cc

Index: chrome/browser/ui/tabs/tab_utils.cc
diff --git a/chrome/browser/ui/tabs/tab_utils.cc b/chrome/browser/ui/tabs/tab_utils.cc
index 541de6371daae0605181aa5fa75f602af1bea2de..a6d5ad6f78ad63cc824e794de52a9e97bce0b9c9 100644
--- a/chrome/browser/ui/tabs/tab_utils.cc
+++ b/chrome/browser/ui/tabs/tab_utils.cc
@@ -4,6 +4,7 @@
 
 #include "chrome/browser/ui/tabs/tab_utils.h"
 
+#include "chrome/browser/media/audio_stream_indicator.h"
 #include "chrome/browser/media/media_capture_devices_dispatcher.h"
 #include "chrome/browser/media/media_stream_capture_indicator.h"
 #include "content/public/browser/render_process_host.h"
@@ -34,4 +35,10 @@ bool ShouldShowRecordingIndicator(content::WebContents* contents) {
          indicator->IsBeingMirrored(render_process_id, render_view_id);
 }
 
+bool ShouldShowAudioIndicator(content::WebContents* contents) {
+  AudioStreamIndicator* audio_indicator =
+      MediaCaptureDevicesDispatcher::GetInstance()->GetAudioStreamIndicator();
+  return audio_indicator->IsPlayingAudio(contents);
+}
+
 }  // namespace chrome