services/ui: Create a proper component for the client-lib.

services/ui/public/cpp/scoped_window_ptr.h

 // Copyright 2015 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 SERVICES_UI_PUBLIC_CPP_SCOPED_WINDOW_PTR_H_
 #define SERVICES_UI_PUBLIC_CPP_SCOPED_WINDOW_PTR_H_
 
 #include "base/macros.h"
+#include "services/ui/public/cpp/ui_export.h"
 #include "services/ui/public/cpp/window_observer.h"
 
 namespace ui {
 
 // Wraps a Window, taking overship of the Window. Also deals with Window being
 // destroyed while ScopedWindowPtr still exists.
-class ScopedWindowPtr : public WindowObserver {
+class UI_EXPORT ScopedWindowPtr : public WindowObserver {
  public:
   explicit ScopedWindowPtr(Window* window);
   ~ScopedWindowPtr() override;
 
   // Destroys |window|. If |window| is a root of the WindowManager than the
   // WindowManager is destroyed (which in turn destroys |window|).
   //
   // NOTE: this function (and class) are only useful for clients that only
   // ever have a single root.
   static void DeleteWindowOrWindowManager(Window* window);
 
   Window* window() { return window_; }
   const Window* window() const { return window_; }
 
  private:
   void DetachFromWindow();
 
   void OnWindowDestroying(Window* window) override;
 
   Window* window_;
 
   DISALLOW_COPY_AND_ASSIGN(ScopedWindowPtr);
 };
 
 }  // namespace ui
 
 #endif  // SERVICES_UI_PUBLIC_CPP_SCOPED_WINDOW_PTR_H_