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

ui/events/event_targeter.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/events/event_targeter.h"
 
 #include "ui/events/event.h"
 #include "ui/events/event_target.h"
 #include "ui/events/event_target_iterator.h"
 
@@ skipping 14 matching lines @@
   return root;
 }
 
 EventTarget* EventTargeter::FindTargetForLocatedEvent(EventTarget* root,
                                                       LocatedEvent* event) {
   scoped_ptr<EventTargetIterator> iter = root->GetChildIterator();
   if (iter) {
     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);
   }
   return root->CanAcceptEvent(*event) ? root : NULL;
 }
 
 bool EventTargeter::SubtreeShouldBeExploredForEvent(EventTarget* target,
                                                     const LocatedEvent& event) {
   return true;
 }
 
 }  // namespace ui