Set up the infrastructure for Extension event metrics.

chrome/browser/signin/easy_unlock_service_regular.cc

 // Copyright 2014 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/signin/easy_unlock_service_regular.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/prefs/pref_service.h"
 #include "base/prefs/scoped_user_pref_update.h"
@@ skipping 239 matching lines @@
     LOG(ERROR)
         << "Start auto pairing when there is another auto pairing requested.";
     callback.Run(false, std::string());
     return;
   }
 
   auto_pairing_callback_ = callback;
 
   scoped_ptr<base::ListValue> args(new base::ListValue());
   scoped_ptr<extensions::Event> event(new extensions::Event(
+      extensions::events::UNKNOWN,
       extensions::api::easy_unlock_private::OnStartAutoPairing::kEventName,
       args.Pass()));
   extensions::EventRouter::Get(profile())->DispatchEventWithLazyListener(
        extension_misc::kEasyUnlockAppId, event.Pass());
 }
 
 void EasyUnlockServiceRegular::SetAutoPairingResult(
     bool success,
     const std::string& error) {
   DCHECK(!auto_pairing_callback_.is_null());
@@ skipping 131 matching lines @@
       new base::DictionaryValue());
   user_prefs_dict->SetBooleanWithoutPathExpansion(
       prefs::kEasyUnlockProximityRequired,
       profile_prefs->GetBoolean(prefs::kEasyUnlockProximityRequired));
 
   DictionaryPrefUpdate update(local_state,
                               prefs::kEasyUnlockLocalStateUserPrefs);
   std::string user_email = GetUserEmail();
   update->SetWithoutPathExpansion(user_email, user_prefs_dict.Pass());
 }