Desktop Aura: Allow tab drags out of window.

ui/base/event.cc

Index: ui/base/event.cc
diff --git a/ui/base/event.cc b/ui/base/event.cc
index f8ab8b6c59b009dd93e54d453fbcd28e6a28a748..f049fa5ad05985761050681c6162904e42bcc686 100644
--- a/ui/base/event.cc
+++ b/ui/base/event.cc
@@ -100,7 +100,8 @@ LocatedEvent::LocatedEvent(const base::NativeEvent& native_event)
             EventTypeFromNative(native_event),
             EventFlagsFromNative(native_event)),
       location_(EventLocationFromNative(native_event)),
-      root_location_(location_) {
+      root_location_(location_),
+      system_location_(ui::EventSystemLocationFromNative(native_event)) {
 }
 
 LocatedEvent::LocatedEvent(EventType type,
@@ -109,13 +110,15 @@ LocatedEvent::LocatedEvent(EventType type,
                            int flags)
     : Event(type, flags),
       location_(location),
-      root_location_(root_location) {
+      root_location_(root_location),
+      system_location_(-1, -1) {
 }
 
 LocatedEvent::LocatedEvent(const LocatedEvent& model)
     : Event(model),
       location_(model.location_),
-      root_location_(model.root_location_) {
+      root_location_(model.root_location_),
+      system_location_(model.system_location_) {
 }
 
 void LocatedEvent::UpdateForRootTransform(const Transform& root_transform) {