Allow a LocatedEvent to be passed to MenuButton, so the ink drop animation is centered on the click…

ui/views/controls/button/menu_button.h

Index: ui/views/controls/button/menu_button.h
diff --git a/ui/views/controls/button/menu_button.h b/ui/views/controls/button/menu_button.h
index b0ddf33115211df9b758287c852394687f50e738..819b9f81b36f961c742d73807b1198a6b2ff8800 100644
--- a/ui/views/controls/button/menu_button.h
+++ b/ui/views/controls/button/menu_button.h
@@ -32,7 +32,9 @@ class VIEWS_EXPORT MenuButton : public LabelButton {
   class VIEWS_EXPORT PressedLock {
    public:
     explicit PressedLock(MenuButton* menu_button);
-    PressedLock(MenuButton* menu_button, bool is_sibling_menu_show);
+    PressedLock(MenuButton* menu_button,
+                bool is_sibling_menu_show,
+                const ui::LocatedEvent* event);

[sky, 2017/04/21 20:32:33]

Document event.

     ~PressedLock();
 
    private:
@@ -109,7 +111,8 @@ class VIEWS_EXPORT MenuButton : public LabelButton {
   // set the state accordingly. The ink drop is snapped to the final ACTIVATED
   // state if |snap_ink_drop_to_activated| is true, otherwise the ink drop will
   // be animated to the ACTIVATED node_data.
-  void IncrementPressedLocked(bool snap_ink_drop_to_activated);
+  void IncrementPressedLocked(bool snap_ink_drop_to_activated,
+                              const ui::LocatedEvent* event);

[sky, 2017/04/21 20:32:33]

Please document |event| and say it may be null.

   void DecrementPressedLocked();
 
   // Compute the maximum X coordinate for the current screen. MenuButtons