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

ash/common/shelf/shelf_layout_manager.cc

 // 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.
 
 #include "ash/common/shelf/shelf_layout_manager.h"
 
 #include <algorithm>
 #include <cmath>
 #include <vector>
 
@@ skipping 550 matching lines @@
   CalculateTargetBounds(state_, &target_bounds);
   UpdateBoundsAndOpacity(
       target_bounds, true /* animate */, true /* change_work_area */,
       delay_background_change ? update_shelf_observer_ : NULL);
 
   // The delegate must be notified after |state_| is updated so that it can
   // query the new target bounds.
   ShelfDelegate* shelf_delegate = WmShell::Get()->shelf_delegate();
   DCHECK(shelf_delegate);
   if (old_state.visibility_state != state_.visibility_state)
-    shelf_delegate->OnShelfVisibilityStateChanged(shelf_widget_->shelf());
+    shelf_delegate->OnShelfVisibilityStateChanged(wm_shelf_);
 
   // OnAutoHideStateChanged Should be emitted when:
   //  - firstly state changed to auto-hide from other state
   //  - or, auto_hide_state has changed
   if ((old_state.visibility_state != state_.visibility_state &&
        state_.visibility_state == SHELF_AUTO_HIDE) ||
       old_state.auto_hide_state != state_.auto_hide_state) {
-    shelf_delegate->OnShelfAutoHideStateChanged(shelf_widget_->shelf());
+    shelf_delegate->OnShelfAutoHideStateChanged(wm_shelf_);
     FOR_EACH_OBSERVER(ShelfLayoutManagerObserver, observers_,
                       OnAutoHideStateChanged(state_.auto_hide_state));
   }
 }
 
 void ShelfLayoutManager::UpdateBoundsAndOpacity(
     const TargetBounds& target_bounds,
     bool animate,
     bool change_work_area,
     ui::ImplicitAnimationObserver* observer) {
@@ skipping 588 matching lines @@
   gesture_drag_status_ = GESTURE_DRAG_NONE;
 }
 
 int ShelfLayoutManager::GetShelfInsetsForAutoHide() const {
   if (invisible_auto_hide_shelf_)
     return 0;
   return GetShelfConstant(SHELF_INSETS_FOR_AUTO_HIDE);
 }
 
 }  // namespace ash