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 d59ff70ae5017f478bb676ccea6c496387cdf5de..a90acf03d916f912b708ea765d9efc1ac8d33147 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();

[miu, 2016/05/16 20:05:35]

IIUC, closing_event_time_ needs to be changed to be of type base::TimeTicks.

[majidvp, 2016/05/21 01:38:00]

It should be eventually but I prefer to make that change in a
separate patch. 

This value get initialized from MenuRunner::closing_event_time.
I din't want to change that interface in this patch to contain the
scope. But I have a TODO in menu_controller.h about
the need for this change.

   // If the current (press down) event is a repost event, the time stamp of
   // these two events should be the same.