Enables hot-tracking for overflow extension buttons in the app menu

ui/views/controls/menu/menu_controller.h

Index: ui/views/controls/menu/menu_controller.h
diff --git a/ui/views/controls/menu/menu_controller.h b/ui/views/controls/menu/menu_controller.h
index 88b00cc80aaefc60be33c1534db9407cbdc5568c..b486c937d8c6e2a339f90e11c4397ca9cd4341f3 100644
--- a/ui/views/controls/menu/menu_controller.h
+++ b/ui/views/controls/menu/menu_controller.h
@@ -498,11 +498,10 @@ class VIEWS_EXPORT MenuController : public WidgetObserver {
   void SelectByChar(base::char16 key);
 
   // For Windows and Aura we repost an event which dismisses the |source| menu.
-  // The menu is also canceled dependent on the target of the event. The event
-  // is then reprocessed to cause its result if the menu had not been present.
-  // On non-aura Windows, a new mouse event is generated and posted to
-  // the window (if there is one) at the location of the event. On
-  // aura, the event is reposted on the RootWindow.
+  // The menu may also be canceled depending on the target of the event. |event|
+  // is then processed without the menu present. On non-aura Windows, a new
+  // mouse event is generated and posted to the window (if there is one) at the
+  // location of the event. On aura, the event is reposted on the RootWindow.
   void RepostEventAndCancel(SubmenuView* source, const ui::LocatedEvent* event);
 
   // Sets the drop target to new_item.
@@ -557,6 +556,10 @@ class VIEWS_EXPORT MenuController : public WidgetObserver {
   void HandleMouseLocation(SubmenuView* source,
                            const gfx::Point& mouse_location);
 
+  // Sets hot-tracked state to the first focusable descendant view of |item|.
+  void SetInitialHotTrackedView(MenuItemView* item,
+                                SelectionIncrementDirectionType direction);
+
   // The active instance.
   static MenuController* active_instance_;