arc: Use incognito profile for OptIn and cookie fetcher

chrome/browser/chromeos/arc/arc_auth_ui.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/chromeos/arc/arc_auth_ui.h"
 
 #include "chrome/browser/chromeos/arc/arc_auth_service.h"
 #include "chrome/browser/ui/webui/chrome_web_contents_handler.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/web_contents.h"
@@ skipping 80 matching lines @@
   if (target_url_.GetOrigin() != current_url.GetOrigin() ||
       target_url_.path() != current_url.path()) {
     return;
   }
 
   auth_fetcher_.reset(
       new ArcAuthFetcher(browser_context_->GetRequestContext(), this));
 }
 
 void ArcAuthUI::OnAuthCodeFetched(const std::string& auth_code) {
-  ArcAuthService::Get()->SetAuthCodeAndStartArc(auth_code);
+  delegate_->OnAuthCodeFetchedFromUI(auth_code);
 }
 
 void ArcAuthUI::OnAuthCodeNeedUI() {}
 
 void ArcAuthUI::OnAuthCodeFailed() {}
 
 }  // namespace arc