chromeos: Refactor shelf to create ShelfView earlier in startup

ash/shelf/wm_shelf.h

 // Copyright 2016 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_WM_SHELF_H_
 #define ASH_SHELF_WM_SHELF_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
@@ skipping 15 matching lines @@
 class ShelfBezelEventHandler;
 class ShelfLayoutManager;
 class ShelfLayoutManagerTest;
 class ShelfLockingManager;
 class ShelfView;
 class ShelfWidget;
 class StatusAreaWidget;
 class WmShelfObserver;
 class WmWindow;
 
-// Controller for the shelf state. Exists for the lifetime of each root window
-// controller. Note that the shelf widget may not be created until after login.

[James Cook, 2017/05/16 21:32:35]

This bit about the widget was a lie.

[msw, 2017/05/16 22:42:00]

Acknowledged.

+// Controller for the shelf state. One per display, because each display might
+// have different shelf alignment, autohide, etc. Exists for the lifetime of the
+// root window controller.
 class ASH_EXPORT WmShelf : public ShelfLayoutManagerObserver {

[msw, 2017/05/16 22:42:00]

Should we rename this to Shelf at some point? :D

[James Cook, 2017/05/17 16:16:13]

Yeah. Or ShelfController (and merge with the existing ShelfController? or rename
that one too?).

Whee, renames.

We should talk about when to do this. Now-ish would be good, since we're right
before the branch.

  public:
   WmShelf();
   ~WmShelf() override;
 
   // Returns the shelf for the display that |window| is on. Note that the shelf
   // widget may not exist, or the shelf may not be visible.
   static WmShelf* ForWindow(WmWindow* window);
 
   // Returns if shelf alignment options are enabled, and the user is able to
   // adjust the alignment (eg. not allowed in guest and supervised user modes).
   static bool CanChangeShelfAlignment();
 
   void CreateShelfWidget(WmWindow* root);
   void ShutdownShelfWidget();
   void DestroyShelfWidget();
 
   ShelfLayoutManager* shelf_layout_manager() const {
     return shelf_layout_manager_;
   }
 
   ShelfWidget* shelf_widget() { return shelf_widget_.get(); }
 
-  // Creates the shelf view.
-  void CreateShelfView();
-
   // TODO(jamescook): Eliminate this method.
-  void ShutdownShelf();
-
-  // True after the ShelfView has been created (e.g. after login).
-  bool IsShelfInitialized() const;
+  void NotifyShelfInitialized();
 
   // Returns the window showing the shelf.
   WmWindow* GetWindow();
 
   ShelfAlignment alignment() const { return alignment_; }
   // TODO(jamescook): Replace with alignment().
   ShelfAlignment GetAlignment() const { return alignment_; }
   void SetAlignment(ShelfAlignment alignment);
 
   // Returns true if the shelf alignment is horizontal (i.e. at the bottom).
@@ skipping 73 matching lines @@
  private:
   class AutoHideEventHandler;
   friend class ShelfLayoutManagerTest;
 
   // Layout manager for the shelf container window. Instances are constructed by
   // ShelfWidget and lifetimes are managed by the container windows themselves.
   ShelfLayoutManager* shelf_layout_manager_ = nullptr;
 
   std::unique_ptr<ShelfWidget> shelf_widget_;
 
-  // Internal implementation detail. Do not expose externally. Owned by views
-  // hierarchy. Null before login and in secondary display init.
-  ShelfView* shelf_view_ = nullptr;
-
   // These initial values hide the shelf until user preferences are available.
   ShelfAlignment alignment_ = SHELF_ALIGNMENT_BOTTOM_LOCKED;
   ShelfAutoHideBehavior auto_hide_behavior_ = SHELF_AUTO_HIDE_ALWAYS_HIDDEN;
 
   // Sets shelf alignment to bottom during login and screen lock.
   std::unique_ptr<ShelfLockingManager> shelf_locking_manager_;
 
   base::ObserverList<WmShelfObserver> observers_;
 
   // Forwards mouse and gesture events to ShelfLayoutManager for auto-hide.
   // TODO(mash): Facilitate simliar functionality in mash: crbug.com/631216
   std::unique_ptr<AutoHideEventHandler> auto_hide_event_handler_;
 
   // Forwards touch gestures on a bezel sensor to the shelf.
   // TODO(mash): Facilitate simliar functionality in mash: crbug.com/636647
   std::unique_ptr<ShelfBezelEventHandler> bezel_event_handler_;
 
   DISALLOW_COPY_AND_ASSIGN(WmShelf);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELF_WM_SHELF_H_