Mark mouse events created for Enter/Leave notify as synthesized as they're not real mouse events.

ui/aura/root_window_host_x11.cc

Index: ui/aura/root_window_host_x11.cc
diff --git a/ui/aura/root_window_host_x11.cc b/ui/aura/root_window_host_x11.cc
index 0d00318f2a31b70b8fa0cb798da9ac72166c1680..ec9c2ab26a032963c02aaeda1605b916b531d1c8 100644
--- a/ui/aura/root_window_host_x11.cc
+++ b/ui/aura/root_window_host_x11.cc
@@ -461,6 +461,8 @@ bool RootWindowHostX11::Dispatch(const base::NativeEvent& event) {
     case EnterNotify:
     case LeaveNotify: {
       ui::MouseEvent mouse_event(xev);
+      // Mark as synthesized as this is not real mouse event.
+      mouse_event.set_flags(mouse_event.flags() | ui::EF_IS_SYNTHESIZED);

[sky, 2013/08/06 21:11:05]

This seems like a real event to me. Why the synthesized? Is the bug that on
showing we should ignore and not here?

[sadrul, 2013/08/06 21:18:51]

My understanding is the EF_IS_SYNTHESIZED is set here since the Enter/Leave
events are system-generated events (by x11) as opposed to user-generated Motion
etc. events

[oshima, 2013/08/06 21:20:32]

This creates mouse MOVE event, even though mouse doesn't move,
hence synthesized. (MOVE event is generated separately when a mouse
enters by move)
Right now, I've seen this only in test bots so far, although
this can happen in real device. I can file if you want. let me know.

[sky, 2013/08/06 21:37:47]

Then should the synthesized be on the move and not this?

       TranslateAndDispatchMouseEvent(&mouse_event);
       break;
     }