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 030faa810d10a889f644f2e14113771b12b4f14a..bb8361fafd00f7f91245bdb1fed7817e1874f6c8 100644
--- a/ui/views/animation/ink_drop_host_view.h
+++ b/ui/views/animation/ink_drop_host_view.h
@@ -38,6 +38,16 @@ class VIEWS_EXPORT InkDropHostView : public View, public InkDropHost {
   void set_ink_drop_size(const gfx::Size& size) { ink_drop_size_ = size; }
 
  protected:
+  // Used in SetHasInkDrop() to specify whether the ink drop effect is enabled
+  // or not for the view. In case of having an ink drop, it also specifies
+  // whether the default gesture event handler for the ink drop should be
+  // installed or the subclass will handle gesture events itself.
+  enum InkDropType {
+    NO_INK_DROP,
+    INK_DROP_WITHOUT_GESTURE_HANDLING,
+    INK_DROP_WITH_GESTURE_HANDLING,
+  };
+
   static const int kInkDropSmallCornerRadius;
 
   void set_ink_drop_visible_opacity(float visible_opacity) {
@@ -84,7 +94,7 @@ class VIEWS_EXPORT InkDropHostView : public View, public InkDropHost {
   // Toggle to enable/disable an InkDrop on this View.  Descendants can override
   // CreateInkDropHighlight() and CreateInkDropRipple() to change the look/feel
   // of the InkDrop.
-  void SetHasInkDrop(bool has_an_ink_drop);
+  void SetHasInkDrop(InkDropType ink_drop_type);

[sky, 2016/06/29 22:58:34]

SetHasInkDrop makes sense when the type is boolean, but now that it's an enum I
think SetInkDropType() makes more sense. WDYT?

[mohsen, 2016/06/30 00:03:45]

Yeah, I had thought of SetInkDropType(), but that might be confused with
different types of InkDrop's and InkDropRipple's that we have. But, I think
InkDropMode and SetInkDropMode() should be good. Renamed.

 
  private:
   class InkDropGestureHandler;