Introduce TabRestoreServiceClient and //chrome implementation.

chrome/browser/sessions/persistent_tab_restore_service.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 CHROME_BROWSER_SESSIONS_PERSISTENT_TAB_RESTORE_SERVICE_H_
 #define CHROME_BROWSER_SESSIONS_PERSISTENT_TAB_RESTORE_SERVICE_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/sessions/tab_restore_service.h"
 #include "chrome/browser/sessions/tab_restore_service_helper.h"
+#include "components/sessions/core/tab_restore_service_client.h"
 
 class Profile;
 
 // Tab restore service that persists data on disk.
 class PersistentTabRestoreService : public TabRestoreService {
  public:
   // Does not take ownership of |time_factory|.
-  PersistentTabRestoreService(Profile* profile,
-                              TimeFactory* time_factory);
+  PersistentTabRestoreService(
+      Profile* profile,
+      scoped_ptr<sessions::TabRestoreServiceClient> client,
+      TimeFactory* time_factory);
 
   ~PersistentTabRestoreService() override;
 
   // TabRestoreService:
   void AddObserver(TabRestoreServiceObserver* observer) override;
   void RemoveObserver(TabRestoreServiceObserver* observer) override;
   void CreateHistoricalTab(content::WebContents* contents, int index) override;
   void BrowserClosing(TabRestoreServiceDelegate* delegate) override;
   void BrowserClosed(TabRestoreServiceDelegate* delegate) override;
   void ClearEntries() override;
@@ skipping 14 matching lines @@
 
  private:
   friend class PersistentTabRestoreServiceTest;
 
   class Delegate;
 
   // Exposed for testing.
   Entries* mutable_entries();
   void PruneEntries();
 
+  scoped_ptr<sessions::TabRestoreServiceClient> client_;
   scoped_ptr<Delegate> delegate_;
   TabRestoreServiceHelper helper_;
 
   DISALLOW_COPY_AND_ASSIGN(PersistentTabRestoreService);
 };
 
 #endif  // CHROME_BROWSER_SESSIONS_PERSISTENT_TAB_RESTORE_SERVICE_H_