Disable first run for the New Tab Cold perf test....

chrome/browser/dom_ui/new_tab_ui.h

 // Copyright (c) 2006-2008 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.
 
 #ifndef CHROME_BROWSER_DOM_UI_NEW_TAB_UI_H_
 #define CHROME_BROWSER_DOM_UI_NEW_TAB_UI_H_
 
 #include "chrome/browser/dom_ui/dom_ui.h"
 #include "chrome/common/notification_registrar.h"
 
@@ skipping 13 matching lines @@
   ~NewTabUI();
 
   static void RegisterUserPrefs(PrefService* prefs);
 
   // Whether we should use the old new tab page.
   static bool UseOldNewTabPage();
 
   // Whether we should disable the web resources backend service
   static bool WebResourcesEnabled();
 
- private:
+  // Whether we should disable the first run notification based on the command
+  // line switch.
+  static bool FirstRunDisabled();
+
+private:
   void Observe(NotificationType type,
                const NotificationSource& source,
                const NotificationDetails& details);
 
   NotificationRegistrar registrar_;
 
   // The message id that should be displayed in this NewTabUIContents
   // instance's motd area.
   int motd_message_id_;
 
   // Whether the user is in incognito mode or not, used to determine
   // what HTML to load.
   bool incognito_;
 
   DISALLOW_COPY_AND_ASSIGN(NewTabUI);
 };
 
 #endif  // CHROME_BROWSER_DOM_UI_NEW_TAB_UI_H_