Added material design mouse hover feedback support.

chrome/browser/ui/views/toolbar/toolbar_button.h

Index: chrome/browser/ui/views/toolbar/toolbar_button.h
diff --git a/chrome/browser/ui/views/toolbar/toolbar_button.h b/chrome/browser/ui/views/toolbar/toolbar_button.h
index f607a446475015b860253cf05b3bb0866b107a9d..4b95b8400d11ec1d9b480251bfa005398cbb0931 100644
--- a/chrome/browser/ui/views/toolbar/toolbar_button.h
+++ b/chrome/browser/ui/views/toolbar/toolbar_button.h
@@ -48,10 +48,12 @@ class ToolbarButton : public views::LabelButton,
   void OnMouseReleased(const ui::MouseEvent& event) override;
   // Showing the drop down results in a MouseCaptureLost, we need to ignore it.
   void OnMouseCaptureLost() override;
+  void OnMouseEntered(const ui::MouseEvent& event) override;
   void OnMouseExited(const ui::MouseEvent& event) override;
   void OnGestureEvent(ui::GestureEvent* event) override;
   void GetAccessibleState(ui::AXViewState* state) override;
   scoped_ptr<views::LabelButtonBorder> CreateDefaultBorder() const override;
+  void OnEnabledChanged() override;
 
   // views::ContextMenuController:
   void ShowContextMenuForView(View* source,
@@ -81,6 +83,9 @@ class ToolbarButton : public views::LabelButton,
   }
 
  private:
+  // Updates the |ink_drop_animation_controller_|'s hover state.
+  void UpdateInkDropHoverState();
+
   // views::LabelButton:
   const char* GetClassName() const override;