mash: Remove some WmWindow usage in ash/shelf.

ash/shelf/wm_shelf.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/shelf/wm_shelf.h"
 
 #include "ash/public/cpp/config.h"
 #include "ash/public/cpp/shelf_item_delegate.h"
 #include "ash/public/cpp/shell_window_ids.h"
 #include "ash/root_window_controller.h"
@@ skipping 32 matching lines @@
       : shelf_layout_manager_(shelf_layout_manager) {
     Shell::Get()->AddPreTargetHandler(this);
   }
   ~AutoHideEventHandler() override {
     Shell::Get()->RemovePreTargetHandler(this);
   }
 
   // Overridden from ui::EventHandler:
   void OnMouseEvent(ui::MouseEvent* event) override {
     shelf_layout_manager_->UpdateAutoHideForMouseEvent(
-        event, WmWindow::Get(static_cast<aura::Window*>(event->target())));
+        event, static_cast<aura::Window*>(event->target()));
   }
   void OnGestureEvent(ui::GestureEvent* event) override {
     shelf_layout_manager_->UpdateAutoHideForGestureEvent(
-        event, WmWindow::Get(static_cast<aura::Window*>(event->target())));
+        event, static_cast<aura::Window*>(event->target()));
   }
 
  private:
   ShelfLayoutManager* shelf_layout_manager_;
   DISALLOW_COPY_AND_ASSIGN(AutoHideEventHandler);
 };
 
 // WmShelf ---------------------------------------------------------------------
 
 WmShelf::WmShelf() {}
@@ skipping 306 matching lines @@
 
 void WmShelf::OnBackgroundUpdated(ShelfBackgroundType background_type,
                                   AnimationChangeType change_type) {
   if (background_type == GetBackgroundType())
     return;
   for (auto& observer : observers_)
     observer.OnBackgroundTypeChanged(background_type, change_type);
 }
 
 }  // namespace ash