Don't use staging GAIA if --gaia-url was explicitly specified in command line

chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.cc

 // Copyright 2013 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/webui/chromeos/login/gaia_screen_handler.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/prefs/pref_service.h"
@@ skipping 228 matching lines @@
 
     params.SetString("chromeType", GetChromeDeviceTypeString());
     params.SetString("clientId",
                      GaiaUrls::GetInstance()->oauth2_chrome_client_id());
     if (!command_line->HasSwitch(switches::kGaiaEndpointChromeOS)) {
       command_line->AppendSwitchASCII(switches::kGaiaEndpointChromeOS,
                                       kMinuteMaidPath);
     }
   }
 
-  if (StartupUtils::IsWebviewSigninEnabled()) {
+  if (!command_line->HasSwitch(::switches::kGaiaUrl) &&
+      StartupUtils::IsWebviewSigninEnabled()) {
     // We can't use switch --gaia-url in this case cause we need get
     // auth_code from staging gaia and make all the other auths against prod
     // gaia so user could use all the google services.
+    // TODO(dpolukhin): crbug.com/462204
     const GURL gaia_url = GURL(kStagingGaiaUrl);
     params.SetString("gaiaUrl", gaia_url.spec());
   } else {
     const GURL gaia_url =
         command_line->HasSwitch(::switches::kGaiaUrl)
             ? GURL(command_line->GetSwitchValueASCII(::switches::kGaiaUrl))
             : GaiaUrls::GetInstance()->gaia_url();
     params.SetString("gaiaUrl", gaia_url.spec());
   }
 
@@ skipping 535 matching lines @@
 
 SigninScreenHandlerDelegate* GaiaScreenHandler::Delegate() {
   DCHECK(signin_screen_handler_);
   return signin_screen_handler_->delegate_;
 }
 
 void GaiaScreenHandler::SetSigninScreenHandler(SigninScreenHandler* handler) {
   signin_screen_handler_ = handler;
 }
 }  // namespace chromeos