Implement chrome.downloads.onDeterminingFilename()

chrome/renderer/resources/extensions/event.js

 // 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.
 
   var DCHECK = requireNative('logging').DCHECK;
   // TODO(cduvall/kalman): json_schema shouldn't put things on chromeHidden.
   require('json_schema');
   var eventBindingsNatives = requireNative('event_bindings');
   var AttachEvent = eventBindingsNatives.AttachEvent;
   var DetachEvent = eventBindingsNatives.DetachEvent;
@@ skipping 195 matching lines @@
       listenerIDs = MatchAgainstEventFilter(name, filteringInfo);
 
     var event = attachedNamedEvents[name];
     if (!event)
       return;
 
     var dispatchArgs = function(args) {
       var result = event.dispatch_(args, listenerIDs);
       if (result)
         DCHECK(!result.validationErrors, result.validationErrors);
+      return result;
     };
 
     if (eventArgumentMassagers[name])
       eventArgumentMassagers[name](args, dispatchArgs);
     else
       dispatchArgs(args);
   };
 
   // Test if a named event has any listeners.
   chromeHidden.Event.hasListener = function(name) {
@@ skipping 240 matching lines @@
       if (event)
         event.detach_();
     }
   };
 
   chromeHidden.dispatchError = function(msg) {
     console.error(msg);
   };
 
   chrome.Event = Event;