Adds WmWindow and converts WindowState to use it

ash/wm/window_resizer.h

 // 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.
 
 #ifndef ASH_WM_WINDOW_RESIZER_H_
 #define ASH_WM_WINDOW_RESIZER_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
@@ skipping 39 matching lines @@
   virtual void Drag(const gfx::Point& location, int event_flags) = 0;
 
   // Invoked to complete the drag.
   virtual void CompleteDrag() = 0;
 
   // Reverts the drag.
   virtual void RevertDrag() = 0;
 
   // Returns the target window the resizer was created for.
   aura::Window* GetTarget() const {
-    return window_state_ ? window_state_->window() : NULL;
+    return window_state_ ? window_state_->aura_window() : NULL;
   }
 
   // See comment for |DragDetails::initial_location_in_parent|.
   const gfx::Point& GetInitialLocation() const {
     return window_state_->drag_details()->initial_location_in_parent;
   }
 
   // Drag parameters established when drag starts.
   const DragDetails& details() const { return *window_state_->drag_details(); }
 
@@ skipping 21 matching lines @@
   int GetWidthForDrag(int min_width, int* delta_x);
 
   // Returns the height of the drag.
   int GetHeightForDrag(int min_height, int* delta_y);
 
   DISALLOW_COPY_AND_ASSIGN(WindowResizer);
 };
 
 // Creates a WindowResizer for |window|. This can return a scoped_ptr
 // initialized with NULL if |window| should not be resized nor dragged.
+// TODO(sky): move this to its own file. This is aura specific.
 ASH_EXPORT std::unique_ptr<WindowResizer> CreateWindowResizer(
     aura::Window* window,
     const gfx::Point& point_in_parent,
     int window_component,
     aura::client::WindowMoveSource source);
 
 }  // namespace ash
 
 #endif  // ASH_WM_WINDOW_RESIZER_H_