events: Update EventTargeter to operate on the EventTarget that owns the targeter.

ui/events/event_targeter.cc

Index: ui/events/event_targeter.cc
diff --git a/ui/events/event_targeter.cc b/ui/events/event_targeter.cc
index 41d44426596cee34473be261c1e43741314919d1..50fe7e92051814b2d7d7c6996e1571aa1c1ac1c4 100644
--- a/ui/events/event_targeter.cc
+++ b/ui/events/event_targeter.cc
@@ -32,16 +32,18 @@ EventTarget* EventTargeter::FindTargetForLocatedEvent(EventTarget* root,
     EventTarget* target = root;
     EventTarget* child = NULL;
     while ((child = iter->GetNextTarget())) {
-      if (!SubtreeShouldBeExploredForEvent(child, *event))
+      EventTargeter* targeter = child->GetEventTargeter();
+      if (!targeter)
+        targeter = this;
+      if (!targeter->SubtreeShouldBeExploredForEvent(child, *event))
         continue;
       target->ConvertEventToTarget(child, event);
-      EventTargeter* targeter = child->GetEventTargeter();
+      target = child;
       EventTarget* child_target = targeter ?
           targeter->FindTargetForLocatedEvent(child, event) :
           FindTargetForLocatedEvent(child, event);
       if (child_target)
         return child_target;
-      target = child;
     }
     target->ConvertEventToTarget(root, event);
   }