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

chrome/browser/ui/tabs/tab_utils.h

Index: chrome/browser/ui/tabs/tab_utils.h
diff --git a/chrome/browser/ui/tabs/tab_utils.h b/chrome/browser/ui/tabs/tab_utils.h
index aef6c4ee779ca4c00cff20568c6e413284b28167..aca9cfc9327435e9a45f791ebc11ee187fc88028 100644
--- a/chrome/browser/ui/tabs/tab_utils.h
+++ b/chrome/browser/ui/tabs/tab_utils.h
@@ -17,6 +17,9 @@ bool ShouldShowProjectingIndicator(content::WebContents* contents);
 // Returns whether we should show a recording favicon indicator for this tab.
 bool ShouldShowRecordingIndicator(content::WebContents* contents);
 
+// Returns whether we should show an audio favicon indicator for this tab.
+bool ShouldShowAudioIndicator(content::WebContents* contents);
+
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_UI_TABS_TAB_UTILS_H_