Use NSMenuDelegate for browser action overflow menu to update it upon opening.

chrome/browser/ui/cocoa/extensions/browser_action_button.h

Index: chrome/browser/ui/cocoa/extensions/browser_action_button.h
diff --git a/chrome/browser/ui/cocoa/extensions/browser_action_button.h b/chrome/browser/ui/cocoa/extensions/browser_action_button.h
index 3f1630c8397d3c0d22f8d1d39dfe943e2a27c0cb..6a4d413c69970090bc504765f099256041618ffc 100644
--- a/chrome/browser/ui/cocoa/extensions/browser_action_button.h
+++ b/chrome/browser/ui/cocoa/extensions/browser_action_button.h
@@ -19,10 +19,6 @@ namespace extensions {
 class Extension;
 }
 
-// Fired when the Browser Action's state has changed. Usually the image needs to
-// be updated.
-extern NSString* const kBrowserActionButtonUpdatedNotification;
-
 // Fired on each drag event while the user is moving the button.
 extern NSString* const kBrowserActionButtonDraggingNotification;
 // Fired when the user drops the button.