Set up the infrastructure for Extension event metrics.

chrome/browser/extensions/api/preference/chrome_direct_setting_api.cc

 // Copyright 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 "chrome/browser/extensions/api/preference/chrome_direct_setting_api.h"
 
 #include "base/bind.h"
 #include "base/containers/hash_tables.h"
 #include "base/lazy_instance.h"
 #include "base/prefs/pref_change_registrar.h"
@@ skipping 127 matching lines @@
     scoped_ptr<base::DictionaryValue> result(new base::DictionaryValue);
     result->Set(preference_api_constants::kValue, value->DeepCopy());
     base::ListValue args;
     args.Append(result.release());
 
     for (const scoped_refptr<const extensions::Extension>& extension :
          ExtensionRegistry::Get(profile_)->enabled_extensions()) {
       const std::string& extension_id = extension->id();
       if (router->ExtensionHasEventListener(extension_id, event_name)) {
         scoped_ptr<base::ListValue> args_copy(args.DeepCopy());
-        scoped_ptr<Event> event(new Event(event_name, args_copy.Pass()));
+        scoped_ptr<Event> event(
+            new Event(events::UNKNOWN, event_name, args_copy.Pass()));
         router->DispatchEventToExtension(extension_id, event.Pass());
       }
     }
   }
 }
 
 }  // namespace chromedirectsetting
 }  // namespace extensions