Splits ToplevelWindowEventHandler into two

ash/wm/aura/wm_window_aura.h

 // 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.
 
 #ifndef ASH_WM_AURA_WM_WINDOW_AURA_H_
 #define ASH_WM_AURA_WM_WINDOW_AURA_H_
 
 #include "ash/ash_export.h"
 #include "ash/wm/common/wm_window.h"
 #include "base/macros.h"
@@ skipping 103 matching lines @@
   void Show() override;
   bool IsFocused() const override;
   bool IsActive() const override;
   void Activate() override;
   void Deactivate() override;
   void SetFullscreen() override;
   void Maximize() override;
   void Minimize() override;
   void Unminimize() override;
   std::vector<WmWindow*> GetChildren() override;
+  void ShowResizeShadow(int component) override;
+  void HideResizeShadow() override;
   void SnapToPixelBoundaryIfNecessary() override;
   void AddObserver(WmWindowObserver* observer) override;
   void RemoveObserver(WmWindowObserver* observer) override;
 
  private:
   // aura::WindowObserver:
   void OnWindowHierarchyChanged(const HierarchyChangeParams& params) override;
   void OnWindowStackingChanged(aura::Window* window) override;
   void OnWindowPropertyChanged(aura::Window* window,
                                const void* key,
                                intptr_t old) override;
   void OnWindowBoundsChanged(aura::Window* window,
                              const gfx::Rect& old_bounds,
                              const gfx::Rect& new_bounds) override;
   void OnWindowDestroying(aura::Window* window) override;
   void OnWindowVisibilityChanging(aura::Window* window, bool visible) override;
 
   aura::Window* window_;
 
   base::ObserverList<WmWindowObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(WmWindowAura);
 };
 
 }  // namespace wm
 }  // namespace ash
 
 #endif  // ASH_WM_AURA_WM_WINDOW_AURA_H_