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

services/ui/public/cpp/raster_thread_helper.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_RASTER_THREAD_HELPER_H_
 #define SERVICES_UI_PUBLIC_CPP_RASTER_THREAD_HELPER_H_
 
 #include <memory>
 
 #include "base/macros.h"
+#include "services/ui/public/cpp/ui_export.h"
 
 namespace cc {
 class TaskGraphRunner;
 class SingleThreadTaskGraphRunner;
 }
 
 namespace ui {
 
-class RasterThreadHelper {
+class UI_EXPORT RasterThreadHelper {
  public:
   RasterThreadHelper();
   ~RasterThreadHelper();
 
   cc::TaskGraphRunner* task_graph_runner();
 
  private:
   std::unique_ptr<cc::SingleThreadTaskGraphRunner> task_graph_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(RasterThreadHelper);
 };
 
 }  // namespace ui
 
 #endif  // SERVICES_UI_PUBLIC_CPP_RASTER_THREAD_HELPER_H_