Swap main menu with app-specific menu when app window focused.

chrome/browser/app_controller_mac.h

Index: chrome/browser/app_controller_mac.h
diff --git a/chrome/browser/app_controller_mac.h b/chrome/browser/app_controller_mac.h
index 46d8a051f3328c97b1c4c7ab344bd5879ebd9835..4ea1356fcf3896047bd22994d6db1cacd17d2a29 100644
--- a/chrome/browser/app_controller_mac.h
+++ b/chrome/browser/app_controller_mac.h
@@ -81,6 +81,9 @@ class WorkAreaWatcherObserver;
 
   scoped_ptr<PrefChangeRegistrar> profilePrefRegistrar_;
   PrefChangeRegistrar localPrefRegistrar_;
+
+  // The main menu item showing the name of a currently focused packaged app.
+  base::scoped_nsobject<NSMenuItem> appMenuItem_;
 }
 
 @property(readonly, nonatomic) BOOL startupComplete;