Enable web-based sign in flow by default. Can use command line argument

chrome/browser/ui/startup/startup_browser_creator_impl.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/ui/startup/startup_browser_creator_impl.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 932 matching lines @@
       // Reset the preference so we don't show the welcome page next time.
       prefs->ClearPref(prefs::kShouldShowWelcomePage);
       startup_urls->push_back(GetWelcomePageURL());
     }
   }
 
   // If the sync promo page is going to be displayed then insert it at the front
   // of the list.
   if (SyncPromoUI::ShouldShowSyncPromoAtStartup(profile_, is_first_run_)) {
     GURL continue_url;
-    if (!CommandLine::ForCurrentProcess()->HasSwitch(
-            switches::kUseWebBasedSigninFlow)) {
+    if (!SyncPromoUI::UseWebBasedSigninFlow()) {
       continue_url = GURL(chrome::kChromeUINewTabURL);
     }
 
     SyncPromoUI::DidShowSyncPromoAtStartup(profile_);
     GURL old_url = (*startup_urls)[0];
     (*startup_urls)[0] =
         SyncPromoUI::GetSyncPromoURL(continue_url,
                                      SyncPromoUI::SOURCE_START_PAGE,
                                      false);
 
@@ skipping 75 matching lines @@
 
 #if !defined(OS_WIN) || defined(USE_AURA)
 // static
 bool StartupBrowserCreatorImpl::OpenStartupURLsInExistingBrowser(
     Profile* profile,
     const std::vector<GURL>& startup_urls) {
   return false;
 }
 #endif