Add MD ink drop ripple to shelf app items

ash/shelf/overflow_button.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef ASH_SHELF_OVERFLOW_BUTTON_H_
 #define ASH_SHELF_OVERFLOW_BUTTON_H_
 
 #include "ash/common/shelf/shelf_types.h"
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/views/controls/button/custom_button.h"
 
 namespace ash {
-
+class InkDropButtonListener;
 class Shelf;
 
 // Shelf overflow chevron button.
 class OverflowButton : public views::CustomButton {
  public:
-  OverflowButton(views::ButtonListener* listener, Shelf* shelf);
+  OverflowButton(InkDropButtonListener* listener, Shelf* shelf);
   ~OverflowButton() override;
 
   void OnShelfAlignmentChanged();
 
  private:
   // views::View:
   void OnPaint(gfx::Canvas* canvas) override;
 
+  // views::CustomButton:
+  void NotifyClick(const ui::Event& event) override;
+
   // Helper functions to paint the background and foreground of the button
   // at |bounds|.
   void PaintBackground(gfx::Canvas* canvas, const gfx::Rect& bounds);
   void PaintForeground(gfx::Canvas* canvas, const gfx::Rect& bounds);
 
   // Returns the id of the asset to use for the button backgound based on the
   // current shelf state.
   // TODO(tdanderson): Remove this once the material design shelf is enabled
   // by default. See crbug.com/614453.
   int NonMaterialBackgroundImageId();
 
   // Calculates the bounds of the overflow button based on the shelf alignment.
   // TODO(tdanderson): The button size and bounds need to be adjusted to
   // conform to the material design spec. See crbug.com/617295.
   gfx::Rect CalculateButtonBounds();
 
   // Used for bottom shelf alignment. |bottom_image_| points to
   // |bottom_image_md_| for material design, otherwise it is points to a
   // resource owned by the ResourceBundle.
   // TODO(tdanderson): Remove the non-md code once the material design shelf is
   // enabled by default. See crbug.com/614453.
   const gfx::ImageSkia* bottom_image_;
   gfx::ImageSkia bottom_image_md_;
 
   // Cached rotations of |bottom_image_| used for left and right shelf
   // alignments.
   gfx::ImageSkia left_image_;
   gfx::ImageSkia right_image_;
 
+  InkDropButtonListener* listener_;
   Shelf* shelf_;
 
   DISALLOW_COPY_AND_ASSIGN(OverflowButton);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELF_OVERFLOW_BUTTON_H_