Pushed InkDropHost inheritence up to CustomButton.

ui/views/animation/ink_drop_host.h

 // Copyright 2015 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 UI_VIEWS_ANIMATION_INK_DROP_HOST_H_
 #define UI_VIEWS_ANIMATION_INK_DROP_HOST_H_
 
 #include "base/macros.h"
 #include "ui/gfx/geometry/point.h"
 #include "ui/views/views_export.h"
 
 namespace ui {
 class Layer;
 }  // namespace ui
 
 namespace views {
 
 // Used by the InkDropAnimationController to add and remove the ink drop layers
 // from a host's layer tree. Typically the ink drop layer is added to a View's
 // layer but it can also be added to a View's ancestor layer.
 //
 // Note: Some Views do not own a Layer, but you can use
 // View::SetLayer(new ui::Layer(ui::LAYER_NOT_DRAWN)) to force the View to have
 // a lightweight Layer that can parent the ink drop layer.
 class VIEWS_EXPORT InkDropHost {
  public:
   InkDropHost() {}
   virtual ~InkDropHost() {}
 
-  // Add the |ink_drop_layer| in to a visible layer tree.
+  // Adds the |ink_drop_layer| in to a visible layer tree.
   virtual void AddInkDropLayer(ui::Layer* ink_drop_layer) = 0;
 
   // Removes |ink_drop_layer| from the layer tree.
   virtual void RemoveInkDropLayer(ui::Layer* ink_drop_layer) = 0;
 
   // Returns the Point where the ink drop should be centered.
   // TODO(varkha): This should be moved to InkDropConsumer.
   virtual gfx::Point CalculateInkDropCenter() const = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(InkDropHost);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_ANIMATION_INK_DROP_HOST_H_