aura: Start using EventPrcessor interface for event dispatch.

ui/events/event_dispatcher.cc

 // Copyright (c) 2012 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_dispatcher.h"
 
 #include <algorithm>
 
 #include "ui/events/event_target.h"
 #include "ui/events/event_targeter.h"
@@ skipping 28 matching lines @@
     dispatcher_->OnDispatcherDelegateDestroyed();
 }
 
 Event* EventDispatcherDelegate::current_event() {
   return dispatcher_ ? dispatcher_->current_event() : NULL;
 }
 
 EventDispatchDetails EventDispatcherDelegate::DispatchEvent(EventTarget* target,
                                                             Event* event) {
   CHECK(target);
+  Event::DispatcherApi dispatch_helper(event);
+  dispatch_helper.set_phase(EP_PREDISPATCH);
+  dispatch_helper.set_result(ER_UNHANDLED);
+
   EventDispatchDetails details = PreDispatchEvent(target, event);
-  if (!details.dispatcher_destroyed)
+  if (!event->handled() && !details.dispatcher_destroyed)
     details = DispatchEventToTarget(target, event);
   if (!details.dispatcher_destroyed)
     details = PostDispatchEvent(target, *event);
 
   return details;
 }
 
 EventDispatchDetails EventDispatcherDelegate::PreDispatchEvent(
     EventTarget* target, Event* event) {
   return EventDispatchDetails();
@@ skipping 116 matching lines @@
     return;
   }
 
   base::AutoReset<Event*> event_reset(&current_event_, event);
   handler->OnEvent(event);
   if (!delegate_ && event->cancelable())
     event->StopPropagation();
 }
 
 }  // namespace ui