Indicate in the Window menu which Chrome window has an active sound playing

chrome/browser/ui/browser_window.h

Index: chrome/browser/ui/browser_window.h
diff --git a/chrome/browser/ui/browser_window.h b/chrome/browser/ui/browser_window.h
index b377723a4d64556da41929752ca1cd52cc59ab60..81b7928b1648296edaada9499341c61265f292a5 100644
--- a/chrome/browser/ui/browser_window.h
+++ b/chrome/browser/ui/browser_window.h
@@ -15,6 +15,7 @@
 #include "chrome/browser/ui/exclusive_access/exclusive_access_bubble_type.h"
 #include "chrome/browser/ui/host_desktop.h"
 #include "chrome/browser/ui/sync/one_click_signin_sync_starter.h"
+#include "chrome/browser/ui/tabs/tab_utils.h"
 #include "components/content_settings/core/common/content_settings_types.h"
 #include "components/signin/core/browser/signin_header_helper.h"
 #include "components/translate/core/common/translate_errors.h"
@@ -93,6 +94,12 @@ class BrowserWindow : public ui::BaseWindow {
   // frames may need to refresh their title bar.
   virtual void UpdateTitleBar() = 0;
 
+#if defined(OS_MACOSX)
+  // Update window media state to show if one of the tabs within the window is
+  // playing an audio/video or even if it's playing something but it's muted.
+  virtual void UpdateMediaState(TabMediaState media_state) = 0;

[miu, 2015/10/21 20:06:52]

I'd ask an OWNER (e.g., sky@ or pkasting@) about this, but IMO I wouldn't
declare the virtual method in this header file.  Instead, just declare the
method in the BrowserWindowCocoa class (and then see my comment below).

+#endif
+
   // Invoked when the state of the bookmark bar changes. This is only invoked if
   // the state changes for the current tab, it is not sent when switching tabs.
   virtual void BookmarkBarStateChanged(