Convert WindowOpenDisposition to an enum class.

chrome/browser/ui/extensions/extension_installed_notification.cc

 // Copyright 2016 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/ui/extensions/extension_installed_notification.h"
 
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/extension_util.h"
 #include "chrome/browser/notifications/notification.h"
@@ skipping 51 matching lines @@
   if (!extensions::util::IsAppLaunchable(extension_id_, profile_))
     return;
 
   const extensions::Extension* extension =
       extensions::ExtensionRegistry::Get(profile_)->GetExtensionById(
           extension_id_, extensions::ExtensionRegistry::EVERYTHING);
   if (!extension)
     return;
 
   AppLaunchParams params = CreateAppLaunchParamsUserContainer(
-      profile_, extension, NEW_FOREGROUND_TAB,
+      profile_, extension, WindowOpenDisposition::NEW_FOREGROUND_TAB,
       extensions::SOURCE_INSTALLED_NOTIFICATION);
   OpenApplication(params);
 }
 
 std::string ExtensionInstalledNotification::id() const {
   return kNotificationId;
 }