Change ui::Event::time_stamp from TimeDelta to TimeTicks

ash/shelf/shelf_view.cc

Index: ash/shelf/shelf_view.cc
diff --git a/ash/shelf/shelf_view.cc b/ash/shelf/shelf_view.cc
index 169241fac7a2942f9200dee5b55c6878bc8d8f17..f23d1f13375e16ace1b51c43236e782d1840c7c7 100644
--- a/ash/shelf/shelf_view.cc
+++ b/ash/shelf/shelf_view.cc
@@ -1873,7 +1873,7 @@ bool ShelfView::IsRepostEvent(const ui::Event& event) {
     return false;
 
   base::TimeDelta delta =
-      base::TimeDelta(event.time_stamp() - closing_event_time_);
+      (event.time_stamp() - closing_event_time_) - base::TimeTicks();
   closing_event_time_ = base::TimeDelta();
   // If the current (press down) event is a repost event, the time stamp of
   // these two events should be the same.