Added material design mouse hover feedback support.

chrome/browser/ui/views/bar_control_button.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 CHROME_BROWSER_UI_VIEWS_BAR_CONTROL_BUTTON_H_
 #define CHROME_BROWSER_UI_VIEWS_BAR_CONTROL_BUTTON_H_
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "ui/views/animation/ink_drop_host.h"
@@ skipping 19 matching lines @@
   void SetIcon(gfx::VectorIconId id,
                const base::Callback<SkColor(void)>& get_text_color_callback);
 
   // views::ImageButton:
   void OnThemeChanged() override;
   void OnNativeThemeChanged(const ui::NativeTheme* theme) override;
   void Layout() override;
   bool OnMousePressed(const ui::MouseEvent& event) override;
   void OnGestureEvent(ui::GestureEvent* event) override;
   void OnMouseReleased(const ui::MouseEvent& event) override;
+  void OnMouseEntered(const ui::MouseEvent& event) override;
+  void OnMouseExited(const ui::MouseEvent& event) override;
   void NotifyClick(const ui::Event& event) override;
+  void OnEnabledChanged() override;
 
  private:
+  // Updates the |ink_drop_animation_controller_|'s hover state.
+  void UpdateInkDropHoverState();
+
   // views::InkDropHost:
   void AddInkDropLayer(ui::Layer* ink_drop_layer) override;
   void RemoveInkDropLayer(ui::Layer* ink_drop_layer) override;
 
   gfx::VectorIconId id_;
   base::Callback<SkColor(void)> get_text_color_callback_;
 
   // Animation controller for the ink drop ripple effect.
   scoped_ptr<views::InkDropAnimationController> ink_drop_animation_controller_;
 
   DISALLOW_COPY_AND_ASSIGN(BarControlButton);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_BAR_CONTROL_BUTTON_H_