Enable history counting for time ranges.

components/history/core/browser/history_service.h

Index: components/history/core/browser/history_service.h
diff --git a/components/history/core/browser/history_service.h b/components/history/core/browser/history_service.h
index 56fa1140c7252a5e9c780e0620d2bff7dfede1a7..62267e1b138f8bc0a143cd12bd2ef32f4de211d7 100644
--- a/components/history/core/browser/history_service.h
+++ b/components/history/core/browser/history_service.h
@@ -344,13 +344,15 @@ class HistoryService : public syncer::SyncableService, public KeyedService {
 
   // Statistics ----------------------------------------------------------------
 
-  // Gets the number of URLs as seen in chrome://history with infinite date
-  // range. If a URL is visited in multiple days, the URL is counted once for
-  // each day. For determination of the date, timestamps are converted to dates
-  // using local time.
+  // Gets the number of URLs as seen in chrome://history within the time range
+  // [|begin_time|, |end_time|). Each URL is counted only once per day. For
+  // determination of the date, timestamps are converted to dates using local
+  // time.
   typedef base::Callback<void(HistoryCountResult)> GetHistoryCountCallback;
 
   base::CancelableTaskTracker::TaskId GetHistoryCount(
+      const base::Time& begin_time,
+      const base::Time& end_time,
       const GetHistoryCountCallback& callback,
       base::CancelableTaskTracker* tracker);