Add Worker support for FileSystem API.

chrome/browser/file_system/browser_file_system_callback_dispatcher.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_FILE_SYSTEM_BROWSER_FILE_SYSTEM_CALLBACK_DISPATCHER_H_
 #define CHROME_BROWSER_FILE_SYSTEM_BROWSER_FILE_SYSTEM_CALLBACK_DISPATCHER_H_
 
 #include "webkit/fileapi/file_system_callback_dispatcher.h"
 
 class FileSystemDispatcherHost;
 
 class BrowserFileSystemCallbackDispatcher
     : public fileapi::FileSystemCallbackDispatcher {
  public:
   BrowserFileSystemCallbackDispatcher(FileSystemDispatcherHost* dispatcher_host,
                                       int request_id);
 
   // FileSystemCallbackDispatcher implementation.
   virtual void DidSucceed();
   virtual void DidReadMetadata(const base::PlatformFileInfo& file_info);
   virtual void DidReadDirectory(
       const std::vector<base::file_util_proxy::Entry>& entries,
       bool has_more);
-  virtual void DidOpenFileSystem(const string16& name,
+  virtual void DidOpenFileSystem(const std::string& name,
                                  const FilePath& root_path);
   virtual void DidFail(base::PlatformFileError error_code);
 
  private:
   scoped_refptr<FileSystemDispatcherHost> dispatcher_host_;
   int request_id_;
 };
 
 #endif  // CHROME_BROWSER_FILE_SYSTEM_BROWSER_FILE_SYSTEM_CALLBACK_DISPATCHER_H_