Port History::QueryMostVisitedURLs to use CancelableTaskTracker

chrome/browser/history/history_backend.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_HISTORY_BACKEND_H_
 #define CHROME_BROWSER_HISTORY_HISTORY_BACKEND_H_
 
 #include <set>
 #include <string>
 #include <utility>
@@ skipping 146 matching lines @@
                     QueryResults* query_results);
   void QueryRedirectsFrom(const GURL& url, QueryRedirectsResult* result);
   void QueryRedirectsTo(const GURL& url, QueryRedirectsResult* result);
 
   void GetVisibleVisitCountToHost(const GURL& url,
                                   VisibleVisitCountToHostResult* result);
 
   // Request the |result_count| most visited URLs and the chain of
   // redirects leading to each of these URLs. |days_back| is the
   // number of days of history to use. Used by TopSites.
-  void QueryMostVisitedURLs(
-      scoped_refptr<QueryMostVisitedURLsRequest> request,
-      int result_count,
-      int days_back);
+  void QueryMostVisitedURLs(int result_count,
+                            int days_back,
+                            MostVisitedURLList* result);
 
   // Request the |result_count| URLs and the chain of redirects
   // leading to each of these URLs, filterd and sorted based on the |filter|.
   // If |debug| is enabled, additional data will be computed and provided.
   void QueryFilteredURLs(
       scoped_refptr<QueryFilteredURLsRequest> request,
       int result_count,
       const history::VisitFilter& filter,
       bool debug);
 
-  // QueryMostVisitedURLs without the request.
-  void QueryMostVisitedURLsImpl(int result_count,
-                                int days_back,
-                                MostVisitedURLList* result);
-
   // Computes the most recent URL(s) that the given canonical URL has
   // redirected to and returns true on success. There may be more than one
   // redirect in a row, so this function will fill the given array with the
   // entire chain. If there are no redirects for the most recent visit of the
   // URL, or the URL is not in history, returns false.
   //
   // Backend for QueryRedirectsFrom.
   bool GetMostRecentRedirectsFrom(const GURL& url,
                                   history::RedirectList* redirects);
 
@@ skipping 661 matching lines @@
 
   // Listens for the system being under memory pressure.
   scoped_ptr<base::MemoryPressureListener> memory_pressure_listener_;
 
   DISALLOW_COPY_AND_ASSIGN(HistoryBackend);
 };
 
 }  // namespace history
 
 #endif  // CHROME_BROWSER_HISTORY_HISTORY_BACKEND_H_