Remove dead code

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 10 matching lines @@
 #include "base/metrics/histogram.h"
 #include "base/rand_util.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/time/time.h"
 #include "chrome/browser/autocomplete/history_url_provider.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/favicon/favicon_changed_details.h"
 #include "chrome/browser/history/download_row.h"
 #include "chrome/browser/history/history_db_task.h"
+#include "chrome/browser/history/history_db_task.h"
 #include "chrome/browser/history/history_notifications.h"
 #include "chrome/browser/history/in_memory_history_backend.h"
+#include "chrome/browser/history/in_memory_history_backend.h"
 #include "chrome/browser/history/page_usage_data.h"
 #include "chrome/browser/history/top_sites.h"
 #include "chrome/browser/history/typed_url_syncable_service.h"
+#include "chrome/browser/history/typed_url_syncable_service.h"
 #include "chrome/browser/history/visit_filter.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/importer/imported_favicon_usage.h"
 #include "chrome/common/url_constants.h"
 #include "components/favicon_base/select_favicon_frames.h"
 #include "components/history/core/browser/history_client.h"
 #include "components/history/core/browser/keyword_search_term.h"
 #include "grit/chromium_strings.h"
 #include "grit/generated_resources.h"
 #include "net/base/registry_controlled_domains/registry_controlled_domain.h"
@@ skipping 2697 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