Added HistoryService::GetHistoryCount() and helper functions in components/history

components/history/core/browser/history_service.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.
 
 // The history system runs on a background thread so that potentially slow
 // database operations don't delay the browser. This backend processing is
 // represented by HistoryBackend. The HistoryService's job is to dispatch to
 // that thread.
 //
 // Main thread                       History thread
@@ skipping 649 matching lines @@
   DCHECK(thread_checker_.CalledOnValidThread());
   QueryURLResult* query_url_result = new QueryURLResult();
   return tracker->PostTaskAndReply(
       after_startup_task_runner_.get(), FROM_HERE,
       base::Bind(&HistoryBackend::QueryURL, history_backend_.get(), url,
                  want_visits, base::Unretained(query_url_result)),
       base::Bind(&RunWithQueryURLResult, callback,
                  base::Owned(query_url_result)));
 }
 
+// Statistics ------------------------------------------------------------------

[msramek, 2015/09/14 17:28:16]

nit: Empty line after "---" comment.

[lwchkg, 2015/09/15 14:27:08]

Acknowledged.

+base::CancelableTaskTracker::TaskId HistoryService::GetHistoryCount(
+    const GetHistoryCountCallback& callback,
+    base::CancelableTaskTracker* tracker) {
+  DCHECK(thread_) << "History service being called after cleanup";
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  return tracker->PostTaskAndReplyWithResult(
+      thread_->task_runner().get(), FROM_HERE,
+      base::Bind(&HistoryBackend::GetHistoryCount, history_backend_.get()),
+      callback);
+}
+
 // Downloads -------------------------------------------------------------------
 
 // Handle creation of a download by creating an entry in the history service's
 // 'downloads' table.
 void HistoryService::CreateDownload(
     const DownloadRow& create_info,
     const HistoryService::DownloadCreateCallback& callback) {
   DCHECK(thread_) << "History service being called after cleanup";
   DCHECK(thread_checker_.CalledOnValidThread());
   PostTaskAndReplyWithResult(after_startup_task_runner_.get(), FROM_HERE,
@@ skipping 492 matching lines @@
   return favicon_changed_callback_list_.Add(callback);
 }
 
 void HistoryService::NotifyFaviconsChanged(const std::set<GURL>& page_urls,
                                            const GURL& icon_url) {
   DCHECK(thread_checker_.CalledOnValidThread());
   favicon_changed_callback_list_.Notify(page_urls, icon_url);
 }
 
 }  // namespace history