Revert 177182 - ViewTest.ChangeNativeViewHierarchyFindRoots failure

ui/aura/client/stacking_client.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 UI_AURA_CLIENT_STACKING_CLIENT_H_
 #define UI_AURA_CLIENT_STACKING_CLIENT_H_
 
 #include "ui/aura/aura_export.h"
 
 namespace gfx {
@@ skipping 17 matching lines @@
   // immediately added.
   //
   // TODO(erg): Remove |context|, and maybe after oshima's patch lands,
   // |bounds|.
   virtual Window* GetDefaultParent(
       Window* context,
       Window* window,
       const gfx::Rect& bounds) = 0;
 };
 
+// Set/Get the default stacking client.
+AURA_EXPORT void SetStackingClient(StackingClient* stacking_client);
+StackingClient* GetStackingClient();
+
 // Set/Get a stacking client for a specific window. Setting the stacking client
 // sets the stacking client on the window's RootWindow, not the window itself.
 // Likewise getting obtains it from the window's RootWindow. If |window| is
 // non-NULL it must be in a RootWindow. If |window| is NULL, the default
 // stacking client is used.
 AURA_EXPORT void SetStackingClient(Window* window,
                                    StackingClient* stacking_client);
 StackingClient* GetStackingClient(Window* window);
 
 }  // namespace client
 }  // namespace aura
 
 #endif  // UI_AURA_CLIENT_STACKING_CLIENT_H_