[ash-md] Updated the overflow shelf to change colors based on the wallpaper.

ash/shelf/overflow_bubble_view.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_BUBBLE_VIEW_H_
 #define ASH_SHELF_OVERFLOW_BUBBLE_VIEW_H_
 
 #include "ash/ash_export.h"
+#include "ash/shelf/shelf_background_animator.h"
+#include "ash/shelf/shelf_background_animator_observer.h"
 #include "base/macros.h"
 #include "ui/views/bubble/bubble_dialog_delegate.h"
 
 namespace views {
 class View;
 }
 
 namespace ash {
 class WmShelf;
 
 namespace test {
 class OverflowBubbleViewTestAPI;
 }
 
 // OverflowBubbleView hosts a ShelfView to display overflown items.
 // Exports to access this class from OverflowBubbleViewTestAPI.
-class ASH_EXPORT OverflowBubbleView : public views::BubbleDialogDelegateView {
+class ASH_EXPORT OverflowBubbleView : public views::BubbleDialogDelegateView,
+                                      public ShelfBackgroundAnimatorObserver {
  public:
   explicit OverflowBubbleView(WmShelf* wm_shelf);
   ~OverflowBubbleView() override;
 
   // |anchor| is the overflow button on the main shelf. |shelf_view| is the
   // ShelfView containing the overflow items.
   void InitOverflowBubble(views::View* anchor, views::View* shelf_view);
 
   // views::BubbleDialogDelegateView overrides:
   int GetDialogButtons() const override;
   void OnBeforeBubbleWidgetInit(views::Widget::InitParams* params,
                                 views::Widget* bubble_widget) const override;
   gfx::Rect GetBubbleBounds() override;
 
  private:
   friend class test::OverflowBubbleViewTestAPI;
 
   void ScrollByXOffset(int x_offset);
   void ScrollByYOffset(int y_offset);
 
   // views::View overrides:
   gfx::Size GetPreferredSize() const override;
   void Layout() override;
   void ChildPreferredSizeChanged(views::View* child) override;
   bool OnMouseWheel(const ui::MouseWheelEvent& event) override;
 
   // ui::EventHandler overrides:
   void OnScrollEvent(ui::ScrollEvent* event) override;
 
+  // ShelfBackgroundAnimatorObserver:
+  void UpdateShelfBackground(SkColor color) override;
+
   WmShelf* wm_shelf_;
   views::View* shelf_view_;  // Owned by views hierarchy.
   gfx::Vector2d scroll_offset_;
 
+  ShelfBackgroundAnimator background_animator_;
+
   DISALLOW_COPY_AND_ASSIGN(OverflowBubbleView);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELF_OVERFLOW_BUBBLE_VIEW_H_