Reland of "Apply Shelf/Dock opacity animations for the Material Design style."

ash/shelf/shelf_widget.h

 // Copyright (c) 2012 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_SHELF_WIDGET_H_
 #define ASH_SHELF_SHELF_WIDGET_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
+#include "ash/common/shelf/shelf_background_animator.h"
+#include "ash/common/shelf/shelf_background_animator_observer.h"
 #include "ash/common/shelf/shelf_types.h"
-#include "ash/common/wm/background_animator.h"
 #include "ash/shelf/shelf_layout_manager_observer.h"
 #include "base/macros.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/widget/widget_observer.h"
 
 namespace ash {
 class FocusCycler;
 class Shelf;
 class ShelfLayoutManager;
 class StatusAreaWidget;
 class WmShelfAura;
 class WmWindow;
 class WorkspaceController;
 
 class ASH_EXPORT ShelfWidget : public views::Widget,
                                public views::WidgetObserver,
+                               public ShelfBackgroundAnimatorObserver,
                                public ShelfLayoutManagerObserver {
  public:
   ShelfWidget(WmWindow* wm_shelf_container,
               WmWindow* wm_status_container,
               WmShelfAura* wm_shelf_aura,
               WorkspaceController* workspace_controller);
   ~ShelfWidget() override;
 
   // Returns if shelf alignment option is enabled, and the user is able to
   // adjust the alignment (guest and supervised mode users cannot for example).
@@ skipping 13 matching lines @@
   bool IsShelfHiddenBehindBlackBar() const;
 
   // Causes shelf items to be slightly dimmed (e.g. when a window is maximized).
   void SetDimsShelf(bool dimming);
   bool GetDimsShelf() const;
 
   ShelfLayoutManager* shelf_layout_manager() { return shelf_layout_manager_; }
   Shelf* shelf() const { return shelf_.get(); }
   StatusAreaWidget* status_area_widget() const { return status_area_widget_; }
 
-  void CreateShelf(WmShelfAura* wm_shelf_aura);
+  void CreateShelf();
   void PostCreateShelf();
 
   // Set visibility of the shelf.
   void SetShelfVisibility(bool visible);
   bool IsShelfVisible() const;
 
   // Sets the focus cycler.  Also adds the shelf to the cycle.
   void SetFocusCycler(FocusCycler* focus_cycler);
   FocusCycler* GetFocusCycler();
 
@@ skipping 14 matching lines @@
   // no dimmer active, the function will return -1.
   int GetDimmingAlphaForTest();
 
   // A function to test the bounds of the dimming bar. Returns gfx::Rect() if
   // the dimmer is inactive.
   gfx::Rect GetDimmerBoundsForTest();
 
   // Disable dimming animations for running tests.
   void DisableDimmingAnimationsForTest();
 
+  // ShelfBackgroundAnimatorObserver overrides:
+  void UpdateShelfItemBackground(int alpha) override;
+
   // ShelfLayoutManagerObserver overrides:
   void WillDeleteShelfLayoutManager() override;
 
  private:
   class DelegateView;
 
   // views::Widget:
   void OnMouseEvent(ui::MouseEvent* event) override;
   void OnGestureEvent(ui::GestureEvent* event) override;
 
+  WmShelfAura* wm_shelf_aura_;
+
   // Owned by the shelf container's aura::Window.
   ShelfLayoutManager* shelf_layout_manager_;
   std::unique_ptr<Shelf> shelf_;
   StatusAreaWidget* status_area_widget_;
 
   // |delegate_view_| is the contents view of this widget and is cleaned up
   // during CloseChildWindows of the associated RootWindowController.
   DelegateView* delegate_view_;
-  BackgroundAnimator background_animator_;
+  ShelfBackgroundAnimator background_animator_;
   bool activating_as_fallback_;
 
   DISALLOW_COPY_AND_ASSIGN(ShelfWidget);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELF_SHELF_WIDGET_H_