Topsites become keyedService based.

chrome/browser/history/top_sites.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_HISTORY_TOP_SITES_H_
 #define CHROME_BROWSER_HISTORY_TOP_SITES_H_
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/gtest_prod_util.h"
-#include "base/memory/ref_counted.h"
 #include "base/observer_list.h"
 #include "base/task/cancelable_task_tracker.h"
 #include "components/history/core/browser/history_types.h"
 #include "components/history/core/browser/top_sites_observer.h"
 #include "components/history/core/common/thumbnail_score.h"
+#include "components/keyed_service/core/refcounted_keyed_service.h"
 #include "content/public/browser/notification_observer.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/image/image.h"
 
 class GURL;
 class Profile;
 
 namespace base {
 class FilePath;
 class RefCountedBytes;
 class RefCountedMemory;
 }
 
 namespace history {
 
 class TopSitesCache;
 
 // Interface for TopSites, which stores the data for the top "most visited"
 // sites. This includes a cache of the most visited data from history, as well
 // as the corresponding thumbnails of those sites.
 //
 // Some methods should only be called from the UI thread (see method
 // descriptions below). All others are assumed to be threadsafe.
-class TopSites
-    : public base::RefCountedThreadSafe<TopSites>,
-      public content::NotificationObserver {
+class TopSites : public RefcountedKeyedService,
+                 public content::NotificationObserver {
  public:
   TopSites();
 
   // Initializes TopSites.
   static TopSites* Create(Profile* profile, const base::FilePath& db_name);
 
   // Sets the given thumbnail for the given URL. Returns true if the thumbnail
   // was updated. False means either the URL wasn't known to us, or we felt
   // that our current thumbnail was superior to the given one. Should be called
   // from the UI thread.
@@ skipping 138 matching lines @@
 const int kPrepopulatedPagesCount = 0;
 #else
 const int kPrepopulatedPagesCount = 2;
 #endif
 extern const TopSites::PrepopulatedPage
     kPrepopulatedPages[kPrepopulatedPagesCount];
 
 }  // namespace history
 
 #endif  // CHROME_BROWSER_HISTORY_TOP_SITES_H_