A mouse event created from the same native event will be marked as repeated.

ui/events/event.cc

Index: ui/events/event.cc
diff --git a/ui/events/event.cc b/ui/events/event.cc
index f0804d871cd9ad9790dcdbbb3af924e42e3cc32a..0cdf70d873394a0b5b5bd532df720c1a84ec3eb3 100644
--- a/ui/events/event.cc
+++ b/ui/events/event.cc
@@ -357,6 +357,10 @@ bool MouseEvent::IsRepeatedClickEvent(
       (event2.flags() & ~EF_IS_DOUBLE_CLICK))
     return false;
 
+  // The new event has been created from the same native event.
+  if (event1.time_stamp() == event2.time_stamp())
+    return false;
+
   base::TimeDelta time_difference = event2.time_stamp() - event1.time_stamp();
 
   if (time_difference.InMilliseconds() > kDoubleClickTimeMS)