Set up the infrastructure for Extension event metrics.

chrome/browser/extensions/api/system_indicator/system_indicator_manager.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/system_indicator/system_indicator_manager.h"
 
 #include "base/memory/linked_ptr.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/extensions/extension_action.h"
 #include "chrome/browser/profiles/profile.h"
@@ skipping 64 matching lines @@
     icon_->RemoveObserver(this);
     status_tray_->RemoveStatusIcon(icon_);
   }
 }
 
 void ExtensionIndicatorIcon::OnStatusIconClicked() {
   scoped_ptr<base::ListValue> params(
       api::system_indicator::OnClicked::Create());
 
   EventRouter* event_router = EventRouter::Get(profile_);
-  scoped_ptr<Event> event(new Event(
-      system_indicator::OnClicked::kEventName,
-      params.Pass(),
-      profile_));
+  scoped_ptr<Event> event(new Event(events::UNKNOWN,
+                                    system_indicator::OnClicked::kEventName,
+                                    params.Pass(), profile_));
   event_router->DispatchEventToExtension(
       extension_->id(), event.Pass());
 }
 
 void ExtensionIndicatorIcon::OnIconUpdated() {
   icon_->SetImage(
       icon_factory_.GetIcon(ExtensionAction::kDefaultTabId).AsImageSkia());
 }
 
 ExtensionIndicatorIcon::ExtensionIndicatorIcon(const Extension* extension,
@@ skipping 90 matching lines @@
   if (extension_icon)
     system_indicators_[extension->id()] = make_linked_ptr(extension_icon);
 }
 
 void SystemIndicatorManager::RemoveIndicator(const std::string& extension_id) {
   DCHECK(thread_checker_.CalledOnValidThread());
   system_indicators_.erase(extension_id);
 }
 
 }  // namespace extensions