Remove unnecessary spin in ToolTipController

ui/wm/public/tooltip_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_WM_PUBLIC_TOOLTIP_CLIENT_H_
 #define UI_WM_PUBLIC_TOOLTIP_CLIENT_H_
 
 #include "ui/aura/aura_export.h"
+#include "ui/aura/window.h"
 #include "ui/gfx/font.h"
 
 namespace gfx {
 class Point;
 }
 
 namespace aura {
 class Window;
 namespace client {
 
@@ skipping 26 matching lines @@
 
 // Sets the text for the tooltip. The id is used to determine uniqueness when
 // the text does not change. For example, if the tooltip text does not change,
 // but the id does then the position of the tooltip is updated.
 AURA_EXPORT void SetTooltipText(Window* window,
                                 base::string16* tooltip_text);
 AURA_EXPORT void SetTooltipId(Window* window, void* id);
 AURA_EXPORT const base::string16 GetTooltipText(Window* window);
 AURA_EXPORT const void* GetTooltipId(Window* window);
 
+AURA_EXPORT extern const aura::WindowProperty<void*>* const kTooltipIdKey;
+AURA_EXPORT extern const aura::WindowProperty<base::string16*>* const
+    kTooltipTextKey;
+
 }  // namespace client
 }  // namespace aura
 
 #endif  // UI_WM_PUBLIC_TOOLTIP_CLIENT_H_