ash: Convert ShelfDelegate to use WmShelf* instead of Shelf*

ash/mus/bridge/wm_shelf_mus.cc

 // 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.
 
 #include "ash/mus/bridge/wm_shelf_mus.h"
 
 #include "ash/common/shelf/shelf.h"
 #include "ash/common/shelf/shelf_delegate.h"
 #include "ash/common/shelf/shelf_widget.h"
 #include "ash/common/shell_window_ids.h"
@@ skipping 10 matching lines @@
   WmWindow* root = root_window_controller->GetWindow();
   shelf_widget_.reset(new ShelfWidget(
       root->GetChildByShellWindowId(kShellWindowId_ShelfContainer),
       root->GetChildByShellWindowId(kShellWindowId_StatusContainer), this));
   shelf_.reset(
       new Shelf(this, shelf_widget_->CreateShelfView(), shelf_widget_.get()));
   shelf_widget_->set_shelf(shelf_.get());
   // Must be initialized before the delegate is notified because the delegate
   // may try to access the WmShelf.
   SetShelf(shelf_.get());
-  WmShell::Get()->shelf_delegate()->OnShelfCreated(shelf_.get());
+  WmShell::Get()->shelf_delegate()->OnShelfCreated(this);
   WmShell::Get()->NotifyShelfCreatedForRootWindow(root);
   shelf_widget_->PostCreateShelf();
 }
 
 WmShelfMus::~WmShelfMus() {
   shelf_widget_.reset();
   WmShelf::ClearShelf();
 }
 
 void WmShelfMus::WillDeleteShelfLayoutManager() {
   shelf_widget_->Shutdown();
   WmShelf::WillDeleteShelfLayoutManager();
 }
 
 }  // namespace mus
 }  // namespace ash