Adds WmWindow and converts WindowState to use it

ash/wm/resize_handle_window_targeter.cc

 // Copyright 2014 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/wm/resize_handle_window_targeter.h"
 
 #include "ash/ash_constants.h"
 #include "ash/wm/immersive_fullscreen_controller.h"
 #include "ash/wm/window_state.h"
+#include "ash/wm/window_state_aura.h"
 #include "ui/aura/window.h"
 #include "ui/events/event.h"
 
 namespace ash {
 
 ResizeHandleWindowTargeter::ResizeHandleWindowTargeter(
     aura::Window* window,
     ImmersiveFullscreenController* controller)
     : window_(window),
       immersive_controller_(controller) {
@@ skipping 72 matching lines @@
       aura::WindowTargeter* targeter =
           static_cast<aura::WindowTargeter*>(parent->GetEventTargeter());
       if (targeter)
         return targeter->SubtreeShouldBeExploredForEvent(window, event);
     }
   }
   return aura::WindowTargeter::SubtreeShouldBeExploredForEvent(window, event);
 }
 
 }  // namespace ash