Revert of Port HistoryService::GetVisibleVisitCountToHost to CancelableTaskTracker

chrome/browser/history/history_backend.cc

 // 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.
 
 #include "chrome/browser/history/history_backend.h"
 
 #include <algorithm>
 #include <functional>
 #include <list>
 #include <map>
@@ skipping 1303 matching lines @@
 
   URLID to_url_id = db_->GetRowForURL(to_url, NULL);
   VisitID cur_visit = db_->GetMostRecentVisitForURL(to_url_id, NULL);
   if (!cur_visit)
     return;  // No visits for URL.
 
   GetRedirectsToSpecificVisit(cur_visit, redirects);
 }
 
 void HistoryBackend::GetVisibleVisitCountToHost(
-    const GURL& url,
-    VisibleVisitCountToHostResult* result) {
-  result->count = 0;
-  result->success = db_.get() &&
-                    db_->GetVisibleVisitCountToHost(
-                        url, &result->count, &result->first_visit);
+    scoped_refptr<GetVisibleVisitCountToHostRequest> request,
+    const GURL& url) {
+  if (request->canceled())
+    return;
+  int count = 0;
+  Time first_visit;
+  const bool success = db_.get() &&
+      db_->GetVisibleVisitCountToHost(url, &count, &first_visit);
+  request->ForwardResult(request->handle(), success, count, first_visit);
 }
 
 void HistoryBackend::QueryTopURLsAndRedirects(
     scoped_refptr<QueryTopURLsAndRedirectsRequest> request,
     int result_count) {
   if (request->canceled())
     return;
 
   if (!db_) {
     request->ForwardResult(request->handle(), false, NULL, NULL);
@@ skipping 1470 matching lines @@
   int rank = kPageVisitStatsMaxTopSites;
   std::map<GURL, int>::const_iterator it = most_visited_urls_map_.find(url);
   if (it != most_visited_urls_map_.end())
     rank = (*it).second;
   UMA_HISTOGRAM_ENUMERATION("History.TopSitesVisitsByRank",
                             rank, kPageVisitStatsMaxTopSites + 1);
 }
 #endif
 
 }  // namespace history