mash: Introduce ShowWebDialogWithContainer for webui dialogs

chrome/browser/chromeos/set_time_dialog.h

 // Copyright 2014 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_SET_TIME_DIALOG_H_
 #define CHROME_BROWSER_CHROMEOS_SET_TIME_DIALOG_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/values.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/web_dialogs/web_dialog_delegate.h"
 
 namespace chromeos {
 
 // Set Time dialog for setting the system time, date and time zone.
 class SetTimeDialog : public ui::WebDialogDelegate {
  public:
+  // Shows the dialog as a child of |parent|, for example the webui settings
+  // window.
+  static void ShowDialogInParent(gfx::NativeWindow parent);
+
+  // Shows the dialog in a given container, for example at the login screen
+  // where the general settings window is not available.
+  static void ShowDialogInContainer(int container_id);
+
+ private:
   SetTimeDialog();
   ~SetTimeDialog() override;
 
-  static void ShowDialog(gfx::NativeWindow owning_window);
-
- private:
   // ui::WebDialogDelegate:
   ui::ModalType GetDialogModalType() const override;
   base::string16 GetDialogTitle() const override;
   GURL GetDialogContentURL() const override;
   void GetWebUIMessageHandlers(
       std::vector<content::WebUIMessageHandler*>* handlers) const override;
   void GetDialogSize(gfx::Size* size) const override;
   std::string GetDialogArgs() const override;
   void OnDialogClosed(const std::string& json_retval) override;
   void OnCloseContents(content::WebContents* source,
                        bool* out_close_dialog) override;
   bool ShouldShowDialogTitle() const override;
   bool HandleContextMenu(const content::ContextMenuParams& params) override;
 
   DISALLOW_COPY_AND_ASSIGN(SetTimeDialog);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_SET_TIME_DIALOG_H_