Reland of Moving previews code from components/ to chrome/

components/previews/core/previews_ui_service.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 COMPONENTS_PREVIEWS_CORE_PREVIEWS_UI_SERVICE_H_
 #define COMPONENTS_PREVIEWS_CORE_PREVIEWS_UI_SERVICE_H_
 
 #include <string>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/threading/thread_checker.h"
 #include "base/time/time.h"
 #include "components/previews/core/previews_experiments.h"
+#include "components/previews/core/previews_io_data.h"
 #include "components/previews/core/previews_opt_out_store.h"
 
 class GURL;
 
 namespace base {
 class SingleThreadTaskRunner;
 }
 
 namespace previews {
 class PreviewsIOData;
 
 // A class to manage the UI portion of inter-thread communication between
 // previews/ objects. Created and used on the UI thread.
 class PreviewsUIService {
  public:
   PreviewsUIService(
       PreviewsIOData* previews_io_data,
       const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner,
-      std::unique_ptr<PreviewsOptOutStore> previews_opt_out_store);
+      std::unique_ptr<PreviewsOptOutStore> previews_opt_out_store,
+      const PreviewsIsEnabledCallback& is_enabled_callback);
   virtual ~PreviewsUIService();
 
   // Sets |io_data_| to |io_data| to allow calls from the UI thread to the IO
   // thread. Virtualized in testing.
   virtual void SetIOData(base::WeakPtr<PreviewsIOData> io_data);
 
   // Adds a navigation to |url| to the black list with result |opt_out|.
   void AddPreviewNavigation(const GURL& url, PreviewsType type, bool opt_out);
 
   // Clears the history of the black list between |begin_time| and |end_time|.
   void ClearBlackList(base::Time begin_time, base::Time end_time);
 
  private:
   // The IO thread portion of the inter-thread communication for previews/.
   base::WeakPtr<previews::PreviewsIOData> io_data_;
 
   base::ThreadChecker thread_checker_;
 
   // The IO thread task runner. Used to post tasks to |io_data_|.
   scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
 
   base::WeakPtrFactory<PreviewsUIService> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PreviewsUIService);
 };
 
 }  // namespace previews
 
 #endif  // COMPONENTS_PREVIEWS_CORE_PREVIEWS_UI_SERVICE_H_