Enable history counting for time ranges.

components/history/core/browser/history_backend.h

Index: components/history/core/browser/history_backend.h
diff --git a/components/history/core/browser/history_backend.h b/components/history/core/browser/history_backend.h
index c8f87f252dc3ecda75cab3a746697d98e97d9f05..71f3eb3e63a52d852c29a35190b77a5da9d9ec92 100644
--- a/components/history/core/browser/history_backend.h
+++ b/components/history/core/browser/history_backend.h
@@ -276,11 +276,12 @@ class HistoryBackend : public base::RefCountedThreadSafe<HistoryBackend>,
 
   // 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.
-  HistoryCountResult GetHistoryCount();
+  // 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.
+  HistoryCountResult GetHistoryCount(const base::Time& begin_time,
+                                     const base::Time& end_time);
 
   // Favicon -------------------------------------------------------------------