Do not set the last mouse location from synthesized event

ui/aura/root_window.cc

Index: ui/aura/root_window.cc
diff --git a/ui/aura/root_window.cc b/ui/aura/root_window.cc
index 128a04424d45ae084e9b6ecfbd659e1d1b42979a..34888e097bc9b98574d902a68c2ec65be872b39c 100644
--- a/ui/aura/root_window.cc
+++ b/ui/aura/root_window.cc
@@ -398,6 +398,12 @@ void RootWindow::MoveCursorToInternal(const gfx::Point& root_location,
 ui::EventDispatchDetails RootWindow::DispatchMouseEnterOrExit(
     const ui::MouseEvent& event,
     ui::EventType type) {
+
+  if (event.type() != ui::ET_MOUSE_CAPTURE_CHANGED &&
+      !(event.flags() & ui::EF_IS_SYNTHESIZED)) {
+    SetLastMouseLocation(window(), event.root_location());
+  }

[oshima, 2014/02/11 19:43:38]

This was necessary because EnterOrExit may cause early exit in 
PreDispatchMouseEvent, which means PreDispatchLocatedEvent is not called. Let me
know if there is a better way/place to fix this.

[sadrul, 2014/02/11 21:26:20]

Can you explain this a bit more? The early returns in PreDispatchMouseEvent for
EnterOrExit: are these only for the cases where the |target| is destroyed
(because I think the rest of the early returns are related to the root-window
itself being destroyed)? If so, can we do this in there instead?

+
   if (!mouse_moved_handler_ || !mouse_moved_handler_->delegate())
     return DispatchDetails();
 
@@ -793,7 +799,6 @@ ui::EventDispatchDetails RootWindow::SynthesizeMouseMoveEvent() {
     return details;
   gfx::Point host_mouse_location = root_mouse_location;
   host()->ConvertPointToHost(&host_mouse_location);
-
   ui::MouseEvent event(ui::ET_MOUSE_MOVED,
                        host_mouse_location,
                        host_mouse_location,
@@ -811,10 +816,11 @@ void RootWindow::PreDispatchLocatedEvent(Window* target,
 
   if (!dispatching_held_event_ &&
       (event->IsMouseEvent() || event->IsScrollEvent())) {
-    if (event->type() != ui::ET_MOUSE_CAPTURE_CHANGED)
-      SetLastMouseLocation(window(), event->root_location());
-    if (!(event->flags() & ui::EF_IS_SYNTHESIZED))
+    if (!(event->flags() & ui::EF_IS_SYNTHESIZED)) {

[sadrul, 2014/02/13 04:38:59]

Merge the two if's?

[oshima, 2014/02/13 15:25:32]

Done.

+      if (event->type() != ui::ET_MOUSE_CAPTURE_CHANGED)
+        SetLastMouseLocation(window(), event->root_location());
       synthesize_mouse_move_ = false;
+    }
   }
 }