Make IsTriggerableEvent take Event objects and use it to verify whether tap events should trigger.

ui/views/controls/button/custom_button.h

Index: ui/views/controls/button/custom_button.h
diff --git a/ui/views/controls/button/custom_button.h b/ui/views/controls/button/custom_button.h
index 46a99eac252609b93105fc8052b4b4ba48f38259..0d30ee49624efc3b5e9e2912653c61059f9843a9 100644
--- a/ui/views/controls/button/custom_button.h
+++ b/ui/views/controls/button/custom_button.h
@@ -110,12 +110,12 @@ class VIEWS_EXPORT CustomButton : public Button,
 
   // Returns true if the event is one that can trigger notifying the listener.
   // This implementation returns true if the left mouse button is down.
-  virtual bool IsTriggerableEvent(const MouseEvent& event);
+  virtual bool IsTriggerableEvent(const Event& event);
 
   // Returns true if the button should become pressed when the user
   // holds the mouse down over the button. For this implementation,
   // we simply return IsTriggerableEvent(event).
-  virtual bool ShouldEnterPushedState(const MouseEvent& event);
+  virtual bool ShouldEnterPushedState(const Event& event);
 
   // Overridden from View:
   virtual void ViewHierarchyChanged(bool is_add,