Set up the infrastructure for Extension event metrics.

chrome/browser/extensions/api/tabs/windows_event_router.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 "chrome/browser/extensions/api/tabs/windows_event_router.h"
 
 #include "base/values.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_util.h"
@@ skipping 120 matching lines @@
   }
 
   if (focused_window_id_ == window_id)
     return;
 
   // window_profile is either the default profile for the active window, its
   // incognito profile, or NULL iff the previous profile is losing focus.
   focused_profile_ = window_profile;
   focused_window_id_ = window_id;
 
-  scoped_ptr<Event> event(new Event(windows::OnFocusChanged::kEventName,
+  scoped_ptr<Event> event(new Event(events::UNKNOWN,
+                                    windows::OnFocusChanged::kEventName,
                                     make_scoped_ptr(new base::ListValue())));
   event->will_dispatch_callback =
       base::Bind(&WillDispatchWindowFocusedEvent,
                  static_cast<BrowserContext*>(window_profile),
                  window_id);
   EventRouter::Get(profile_)->BroadcastEvent(event.Pass());
 }
 
 void WindowsEventRouter::DispatchEvent(const std::string& event_name,
                                       Profile* profile,
                                       scoped_ptr<base::ListValue> args) {
-  scoped_ptr<Event> event(new Event(event_name, args.Pass()));
+  scoped_ptr<Event> event(new Event(events::UNKNOWN, event_name, args.Pass()));
   event->restrict_to_browser_context = profile;
   EventRouter::Get(profile)->BroadcastEvent(event.Pass());
 }
 
 }  // namespace extensions