Add JavaScript dialogs functionality to content_shell on Windows

content/shell/shell_javascript_dialog.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 CONTENT_SHELL_SHELL_JAVASCRIPT_DIALOG_H_
 #define CONTENT_SHELL_SHELL_JAVASCRIPT_DIALOG_H_
 #pragma once
 
 #include "content/public/browser/javascript_dialogs.h"
 
@@ skipping 24 matching lines @@
   // Called to cancel a dialog mid-flight.
   void Cancel();
 
  private:
   ShellJavaScriptDialogCreator* creator_;
   JavaScriptDialogCreator::DialogClosedCallback callback_;
 
 #if defined(OS_MACOSX)
   ShellJavaScriptDialogHelper* helper_;  // owned
   NSAlert* alert_; // weak, owned by |helper_|.
-#endif  // defined(OS_MACOSX)
+#elif defined(OS_WIN)
+  ui::JavascriptMessageType message_type_;
+  HWND dialog_win_;
+  string16 message_text_;
+  string16 default_prompt_text_;
+  static INT_PTR CALLBACK DialogProc(HWND dialog, UINT message, WPARAM wparam,
+                                     LPARAM lparam);
+#endif
 
   DISALLOW_COPY_AND_ASSIGN(ShellJavaScriptDialog);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_SHELL_SHELL_JAVASCRIPT_DIALOG_H_