Topsites become keyedService based.

chrome/browser/history/top_sites_impl.h

 // Copyright (c) 2013 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_HISTORY_TOP_SITES_IMPL_H_
 #define CHROME_BROWSER_HISTORY_TOP_SITES_IMPL_H_
 
 #include <list>
 #include <set>
 #include <string>
@@ skipping 65 matching lines @@
   void Shutdown() override;
   base::CancelableTaskTracker::TaskId StartQueryForMostVisited() override;
   bool IsKnownURL(const GURL& url) override;
   const std::string& GetCanonicalURLString(const GURL& url) const override;
   bool IsNonForcedFull() override;
   bool IsForcedFull() override;
   MostVisitedURLList GetPrepopulatePages() override;
   bool loaded() const override;
   bool AddForcedURL(const GURL& url, const base::Time& time) override;
 
+  // RefcountedKeyedService:
+  void ShutdownOnUIThread() override;
+
  protected:
   ~TopSitesImpl() override;
 
  private:
   friend class TopSitesImplTest;
   FRIEND_TEST_ALL_PREFIXES(TopSitesImplTest, DiffMostVisited);
   FRIEND_TEST_ALL_PREFIXES(TopSitesImplTest, DiffMostVisitedWithForced);
 
   typedef base::Callback<void(const MostVisitedURLList&,
                               const MostVisitedURLList&)> PendingCallback;
@@ skipping 160 matching lines @@
 
   // Are we loaded?
   bool loaded_;
 
   DISALLOW_COPY_AND_ASSIGN(TopSitesImpl);
 };
 
 }  // namespace history
 
 #endif  // CHROME_BROWSER_HISTORY_TOP_SITES_IMPL_H_