ash: Explicitly teach various components about ShelfLayoutManager.

ash/system/web_notification/ash_popup_alignment_delegate.h

 // Copyright 2014 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_SYSTEM_WEB_NOTIFICATION_ASH_POPUP_ALIGNMENT_DELEGATE_H_
 #define ASH_SYSTEM_WEB_NOTIFICATION_ASH_POPUP_ALIGNMENT_DELEGATE_H_
 
 #include <stdint.h>
 
 #include "ash/ash_export.h"
@@ skipping 20 matching lines @@
 class WebNotificationTrayTest;
 
 // The PopupAlignmentDelegate subclass for Ash. It needs to handle alignment of
 // the shelf and its autohide state.
 class ASH_EXPORT AshPopupAlignmentDelegate
     : public message_center::PopupAlignmentDelegate,
       public ShelfLayoutManagerObserver,
       public ShellObserver,
       public gfx::DisplayObserver {
  public:
-  AshPopupAlignmentDelegate();
+  explicit AshPopupAlignmentDelegate(ShelfLayoutManager* shelf);
   ~AshPopupAlignmentDelegate() override;
 
   // Start observing the system.
   void StartObserving(gfx::Screen* screen, const gfx::Display& display);
 
   // Sets the current height of the system tray so that the notification toasts
   // can avoid it.
   void SetSystemTrayHeight(int height);
 
   // Overridden from message_center::PopupAlignmentDelegate:
   int GetToastOriginX(const gfx::Rect& toast_bounds) const override;
   int GetBaseLine() const override;
   int GetWorkAreaBottom() const override;
   bool IsTopDown() const override;
   bool IsFromLeft() const override;
   void RecomputeAlignment(const gfx::Display& display) override;
 
  private:
   friend class AshPopupAlignmentDelegateTest;
   friend class WebNotificationTrayTest;
 
   // Get the current alignment of the shelf.
   ShelfAlignment GetAlignment() const;
 
-  // Update |shelf_| and start watching when it's first set. This should not
-  // be done in the constructor because the shelf might not be initialized at
-  // that point.
-  void UpdateShelf();
-
   // Utility function to get the display which should be care about.
   gfx::Display GetCurrentDisplay() const;
 
   // Compute the new work area.
   void UpdateWorkArea();
 
   // Overridden from ShellObserver:
   void OnDisplayWorkAreaInsetsChanged() override;
 
   // Overridden from ShelfLayoutManagerObserver:
@@ skipping 11 matching lines @@
   aura::Window* root_window_;
   ShelfLayoutManager* shelf_;
   int system_tray_height_;
 
   DISALLOW_COPY_AND_ASSIGN(AshPopupAlignmentDelegate);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_WEB_NOTIFICATION_ASH_POPUP_ALIGNMENT_DELEGATE_H_