chromeos: Make enterprise help dialog work in mash, part 1

chrome/browser/chromeos/login/help_app_launcher.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_LOGIN_HELP_APP_LAUNCHER_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_HELP_APP_LAUNCHER_H_
 
 #include <memory>
 
-#include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
-#include "chrome/browser/chromeos/login/ui/login_web_dialog.h"
 #include "ui/gfx/native_widget_types.h"
 
+class GURL;
 class Profile;
 
 namespace chromeos {
 
 // Provides help content during OOBE / login.
 // Based on connectivity state (offline/online) shows help topic dialog
 // or launches HelpApp in BWSI mode.
 class HelpAppLauncher : public base::RefCountedThreadSafe<HelpAppLauncher> {
  public:
   // IDs of help topics available from HelpApp.
   enum HelpTopic {
     // Showed at EULA screen as "Learn more" about stats/crash reports.
     HELP_STATS_USAGE = 183078,
     // Showed whenever there're troubles signing in.
     HELP_CANT_ACCESS_ACCOUNT = 188036,
     // Showed in case when account was disabled.
     HELP_ACCOUNT_DISABLED = 188756,
     // Showed as "Learn more" about enterprise enrolled devices.
     HELP_ENTERPRISE = 2535613,
     // Shown at reset screen as "Learn more" about powerwash/rollback options.
     HELP_POWERWASH = 183084,
     // Shown as "Learn more" about the device attributes.
     HELP_DEVICE_ATTRIBUTES = 6218780,
   };
 
-  // Parent window is used to show dialog.
+  // The dialog is shown as a child of |parent_window|. If |parent_window| is
+  // null then the dialog is placed in the modal dialog container on the primary
+  // display.
   explicit HelpAppLauncher(gfx::NativeWindow parent_window);
 
   // Shows specified help topic.
   void ShowHelpTopic(HelpTopic help_topic_id);
 
  protected:
   virtual ~HelpAppLauncher();
 
  private:
   friend class base::RefCountedThreadSafe<HelpAppLauncher>;
 
   // Shows help topic dialog for specified GURL.
   void ShowHelpTopicDialog(Profile* profile, const GURL& topic_url);
 
   // Parent window which is passed to help dialog.
   gfx::NativeWindow parent_window_;
 
   DISALLOW_COPY_AND_ASSIGN(HelpAppLauncher);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_HELP_APP_LAUNCHER_H_