IPC::ParamTraits for ui::Event (towards ui::Events over mojo IPC)

ui/events/event.cc

Index: ui/events/event.cc
diff --git a/ui/events/event.cc b/ui/events/event.cc
index 21add836568fd5676ea067a08fd1c6c0c7a4e8aa..ca6704b6f8fa5b6e49888074b799c620b7bc90e2 100644
--- a/ui/events/event.cc
+++ b/ui/events/event.cc
@@ -844,6 +844,9 @@ bool KeyEvent::IsRepeated(const KeyEvent& event) {
   return false;
 }
 
+KeyEvent::KeyEvent(EventType type, base::TimeDelta time_stamp, int flags)
+    : Event(type, time_stamp, flags) {}
+
 KeyEvent::KeyEvent(const base::NativeEvent& native_event)
     : Event(native_event,
             EventTypeFromNative(native_event),