Set up the infrastructure for Extension event metrics.

chrome/browser/extensions/api/media_galleries/media_galleries_api.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.
 
 // Implements the Chrome Extensions Media Galleries API.
 
 #include "chrome/browser/extensions/api/media_galleries/media_galleries_api.h"
 
 #include <set>
 #include <string>
@@ skipping 404 matching lines @@
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
   // TODO(tommycli): Remove these CHECKs after fixing https://crbug.com/467627.
   CHECK(profile_);
   EventRouter* router = EventRouter::Get(profile_);
   CHECK(router);
 
   if (!router->ExtensionHasEventListener(extension_id, event_name))
     return;
 
-  scoped_ptr<extensions::Event> event(
-      new extensions::Event(event_name, event_args.Pass()));
+  scoped_ptr<extensions::Event> event(new extensions::Event(
+      extensions::events::UNKNOWN, event_name, event_args.Pass()));
   router->DispatchEventToExtension(extension_id, event.Pass());
 }
 
 void MediaGalleriesEventRouter::OnGalleryChanged(
     const std::string& extension_id, MediaGalleryPrefId gallery_id) {
   MediaGalleries::GalleryChangeDetails details;
   details.type = MediaGalleries::GALLERY_CHANGE_TYPE_CONTENTS_CHANGED;
   details.gallery_id = base::Uint64ToString(gallery_id);
   DispatchEventToExtension(
       extension_id,
@@ skipping 836 matching lines @@
       &MediaGalleriesRemoveAllGalleryWatchFunction::OnPreferencesInit, this));
   return true;
 }
 
 void MediaGalleriesRemoveAllGalleryWatchFunction::OnPreferencesInit() {
   gallery_watch_manager()->RemoveAllWatches(GetProfile(), extension_id());
   SendResponse(true);
 }
 
 }  // namespace extensions