Set up the infrastructure for Extension event metrics.

chrome/browser/extensions/api/sessions/sessions_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/sessions/sessions_api.h"
 
 #include <vector>
 
 #include "base/i18n/rtl.h"
 #include "base/lazy_instance.h"
@@ skipping 601 matching lines @@
 }
 
 SessionsEventRouter::~SessionsEventRouter() {
   if (tab_restore_service_)
     tab_restore_service_->RemoveObserver(this);
 }
 
 void SessionsEventRouter::TabRestoreServiceChanged(
     TabRestoreService* service) {
   scoped_ptr<base::ListValue> args(new base::ListValue());
-  EventRouter::Get(profile_)->BroadcastEvent(make_scoped_ptr(
-      new Event(api::sessions::OnChanged::kEventName, args.Pass())));
+  EventRouter::Get(profile_)->BroadcastEvent(make_scoped_ptr(new Event(
+      events::UNKNOWN, api::sessions::OnChanged::kEventName, args.Pass())));
 }
 
 void SessionsEventRouter::TabRestoreServiceDestroyed(
     TabRestoreService* service) {
   tab_restore_service_ = NULL;
 }
 
 SessionsAPI::SessionsAPI(content::BrowserContext* context)
     : browser_context_(context) {
   EventRouter::Get(browser_context_)->RegisterObserver(this,
@@ skipping 15 matching lines @@
   return g_factory.Pointer();
 }
 
 void SessionsAPI::OnListenerAdded(const EventListenerInfo& details) {
   sessions_event_router_.reset(
       new SessionsEventRouter(Profile::FromBrowserContext(browser_context_)));
   EventRouter::Get(browser_context_)->UnregisterObserver(this);
 }
 
 }  // namespace extensions