Add MD ink drop ripple to app list button

ui/views/animation/ink_drop_host_view.h

Index: ui/views/animation/ink_drop_host_view.h
diff --git a/ui/views/animation/ink_drop_host_view.h b/ui/views/animation/ink_drop_host_view.h
index c3fa8d8cbb9040d5025d6a0c64b14e1d547e69eb..2a3b8fa2e329e73c512685adb36880e80db2db42 100644
--- a/ui/views/animation/ink_drop_host_view.h
+++ b/ui/views/animation/ink_drop_host_view.h
@@ -86,6 +86,11 @@ class VIEWS_EXPORT InkDropHostView : public View, public InkDropHost {
   // of the InkDrop.
   void SetHasInkDrop(bool has_an_ink_drop);
 
+  // An overload of SetHasInkDrop() that takes an extra argument specifying
+  // whether the default gesture handler should be installed for the ink drop or
+  // not. |handles_gesture_event| can only be true when |has_ink_drop| is true.
+  void SetHasInkDrop(bool has_an_ink_drop, bool handles_gesture_event);

[James Cook, 2016/06/23 20:08:08]

Having a method that takes two bools side by side, and only allows 3 states, is
confusing, especially when you already have a single-bool version. I would
prefer that you declare an enum for the 3 states and collapse the two methods
into one like SetHasInkDrop(InkDrop state).

Alternately you could have two methods, SetHasInkDrop() and
SetHandlesGestureEvents().

[mohsen, 2016/06/27 22:17:10]

Right. I believe having two separate methods would also be confusing as one is
only meaningful if the other is set to true. It is also hard to manage
especially if they can be called in any order. Switched to using a 3-valued
enum.

+
  private:
   class InkDropGestureHandler;
   friend class InkDropGestureHandler;