Add first-class support for user scripts

chrome/browser/extensions/convert_user_script.h

+// Copyright (c) 2009 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_EXTENSIONS_CONVERT_USER_SCRIPT_H_
+#define CHROME_BROWSER_EXTENSIONS_CONVERT_USER_SCRIPT_H_
+
+#include <string>
+
+class Extension;
+class FilePath;
+class GURL;
+
+// Wraps the specified user script in an extension. The extension is created
+// unpacked in the system temp dir. Returns a valid extension that the caller
+// should take ownership on success, or NULL and |error| on failure.
+//
+// NOTE: This function does file IO and should not be called on the UI thread.
+Extension* ConvertUserScriptToExtension(const FilePath& user_script,
+                                        const GURL& original_url,
+                                        std::string* error);
+
+#endif  // CHROME_BROWSER_EXTENSIONS_CONVERT_USER_SCRIPT_H_