Add sign in dialog for GCP->print preview integration.

chrome/browser/printing/cloud_print/cloud_print_url.h

 // Copyright (c) 2010 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_PRINTING_CLOUD_PRINT_CLOUD_PRINT_URL_H_
 #define CHROME_BROWSER_PRINTING_CLOUD_PRINT_CLOUD_PRINT_URL_H_
 #pragma once
 
 #include <string>
 
 class GURL;
 class Profile;
 
 // Centralize URL management for the cloud print service.
 class CloudPrintURL {
  public:
   explicit CloudPrintURL(Profile* profile) : profile_(profile) {}
 
   GURL GetCloudPrintServiceURL();
   GURL GetCloudPrintServiceDialogURL();
   GURL GetCloudPrintServiceManageURL();
   GURL GetCloudPrintServiceEnableURL(const std::string& proxy_id);
+  GURL GetCloudPrintSigninURL();
 
   // These aren't derived from the service, but it makes sense to keep all the
   // URLs together, and this gives the unit tests access for testing.
   static GURL GetCloudPrintLearnMoreURL();
   static GURL GetCloudPrintTestPageURL();
 
  private:
   void RegisterPreferences();
 
   Profile* profile_;
 };
 
 #endif  // CHROME_BROWSER_PRINTING_CLOUD_PRINT_CLOUD_PRINT_URL_H_