Snap widgets to pixel boundary on ash

ash/wm/system_modal_container_layout_manager.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_SYSTEM_MODAL_CONTAINER_LAYOUT_MANAGER_H_
 #define ASH_WM_SYSTEM_MODAL_CONTAINER_LAYOUT_MANAGER_H_
 
 #include <vector>
 
 #include "ash/ash_export.h"
+#include "ash/snap_to_pixel_layout_manager.h"
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
-#include "ui/aura/layout_manager.h"
 #include "ui/aura/window_observer.h"
 #include "ui/keyboard/keyboard_controller_observer.h"
 
 namespace aura {
 class Window;
 class EventFilter;
 }
 namespace gfx {
 class Rect;
 }
 namespace views {
 class Widget;
 }
 
 namespace ash {
 
 // LayoutManager for the modal window container.
 // System modal windows which are centered on the screen will be kept centered
 // when the container size changes.
 class ASH_EXPORT SystemModalContainerLayoutManager
-    : public aura::LayoutManager,
+    : public SnapToPixelLayoutManager,
       public aura::WindowObserver,
       public keyboard::KeyboardControllerObserver {
  public:
   explicit SystemModalContainerLayoutManager(aura::Window* container);
   virtual ~SystemModalContainerLayoutManager();
 
   bool has_modal_background() const { return modal_background_ != NULL; }
 
-  // Overridden from aura::LayoutManager:
+  // Overridden from SnapToPixelLayoutManager:
   virtual void OnWindowResized() OVERRIDE;
   virtual void OnWindowAddedToLayout(aura::Window* child) OVERRIDE;
   virtual void OnWillRemoveWindowFromLayout(aura::Window* child) OVERRIDE;
-  virtual void OnWindowRemovedFromLayout(aura::Window* child) OVERRIDE;
-  virtual void OnChildWindowVisibilityChanged(aura::Window* child,
-                                              bool visibile) OVERRIDE;
   virtual void SetChildBounds(aura::Window* child,
                               const gfx::Rect& requested_bounds) OVERRIDE;
 
   // Overridden from aura::WindowObserver:
   virtual void OnWindowPropertyChanged(aura::Window* window,
                                        const void* key,
                                        intptr_t old) OVERRIDE;
   virtual void OnWindowDestroying(aura::Window* window) OVERRIDE;
 
   // Overridden from keyboard::KeyboardControllerObserver:
@@ skipping 46 matching lines @@
 
   // A stack of modal windows. Only the topmost can receive events.
   std::vector<aura::Window*> modal_windows_;
 
   DISALLOW_COPY_AND_ASSIGN(SystemModalContainerLayoutManager);
 };
 
 }  // namespace ash
 
 #endif  // ASH_WM_SYSTEM_MODAL_CONTAINER_LAYOUT_MANAGER_H_