Add notification mechanism when BrowserActionButton's icon has been updated.

chrome/browser/ui/views/toolbar/browser_action_view.h

Index: chrome/browser/ui/views/toolbar/browser_action_view.h
diff --git a/chrome/browser/ui/views/toolbar/browser_action_view.h b/chrome/browser/ui/views/toolbar/browser_action_view.h
index 7d8991964e172bb160ed14f9246e6dfbba420f01..f168f0a40ee7e2fbd127086343c1cda3d98be89d 100644
--- a/chrome/browser/ui/views/toolbar/browser_action_view.h
+++ b/chrome/browser/ui/views/toolbar/browser_action_view.h
@@ -111,6 +111,18 @@ class BrowserActionButton : public views::MenuButton,
                             public content::NotificationObserver,
                             public ExtensionActionIconFactory::Observer {
  public:
+  // The IconObserver will receive a notification when the button's icon has
+  // been updated.
+  class IconObserver {
+   public:
+    virtual ~IconObserver() {}
+    virtual void OnIconUpdated(const gfx::ImageSkia& icon) = 0;
+  };
+
+  void set_icon_observer(IconObserver* icon_observer) {
+    icon_observer_ = icon_observer;
+  }
+
   BrowserActionButton(const extensions::Extension* extension,
                       Browser* browser_,
                       BrowserActionView::Delegate* delegate);
@@ -230,6 +242,8 @@ class BrowserActionButton : public views::MenuButton,
   // Responsible for running the menu.
   scoped_ptr<views::MenuRunner> menu_runner_;
 
+  IconObserver* icon_observer_;

[Finnur, 2014/02/10 10:41:41]

nit: Document.

+
   friend class base::DeleteHelper<BrowserActionButton>;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserActionButton);