Moves ash/wm/common back into ash

ash/wm/common/wm_snap_to_pixel_layout_manager.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_COMMON_WM_SNAP_TO_PIXEL_LAYOUT_MANAGER_H_
 #define ASH_WM_COMMON_WM_SNAP_TO_PIXEL_LAYOUT_MANAGER_H_
 
-#include "ash/wm/common/ash_wm_common_export.h"
+#include "ash/ash_export.h"
 #include "ash/wm/common/wm_layout_manager.h"
 #include "base/macros.h"
 
 namespace ash {
 namespace wm {
 
 // A layout manager that places children's layer at the physical pixel
 // boundaries.
-class ASH_WM_COMMON_EXPORT WmSnapToPixelLayoutManager : public WmLayoutManager {
+class ASH_EXPORT WmSnapToPixelLayoutManager : public WmLayoutManager {
  public:
   WmSnapToPixelLayoutManager();
   ~WmSnapToPixelLayoutManager() override;
 
  protected:
   // Overridden from aura::LayoutManager:
   void OnWindowResized() override;
   void OnWindowAddedToLayout(WmWindow* child) override;
   void OnWillRemoveWindowFromLayout(WmWindow* child) override;
   void OnWindowRemovedFromLayout(WmWindow* child) override;
   void OnChildWindowVisibilityChanged(WmWindow* child, bool visibile) override;
   void SetChildBounds(WmWindow* child,
                       const gfx::Rect& requested_bounds) override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(WmSnapToPixelLayoutManager);
 };
 
 }  // namespace wm
 }  // namespace ash
 
 #endif  // ASH_WM_COMMON_WM_SNAP_TO_PIXEL_LAYOUT_MANAGER_H_