Add FileSystemMountPointProvider::CreateFileReader() which returns appropriate Reader instance

webkit/fileapi/file_system_url_request_job.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 WEBKIT_FILEAPI_FILE_SYSTEM_URL_REQUEST_JOB_H_
 #define WEBKIT_FILEAPI_FILE_SYSTEM_URL_REQUEST_JOB_H_
 #pragma once
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop_proxy.h"
 #include "base/platform_file.h"
 #include "net/http/http_byte_range.h"
 #include "net/url_request/url_request_job.h"
 
 class GURL;
 class FilePath;
 
+namespace webkit_blob {
+class FileReader;
+}
+
 namespace fileapi {
 class FileSystemContext;
-class FileSystemFileReader;
 
 // A request job that handles reading filesystem: URLs
 class FileSystemURLRequestJob : public net::URLRequestJob {
  public:
   FileSystemURLRequestJob(
       net::URLRequest* request,
       FileSystemContext* file_system_context,
       scoped_refptr<base::MessageLoopProxy> file_thread_proxy);
 
   // URLRequestJob methods:
@@ skipping 21 matching lines @@
   void DidGetMetadata(
       base::PlatformFileError error_code,
       const base::PlatformFileInfo& file_info,
       const FilePath& platform_path);
   void DidRead(int result);
   void NotifyFailed(int rv);
 
   FileSystemContext* file_system_context_;
   scoped_refptr<base::MessageLoopProxy> file_thread_proxy_;
   base::WeakPtrFactory<FileSystemURLRequestJob> weak_factory_;
-  scoped_ptr<FileSystemFileReader> reader_;
+  scoped_ptr<webkit_blob::FileReader> reader_;
   bool is_directory_;
   scoped_ptr<net::HttpResponseInfo> response_info_;
   int64 remaining_bytes_;
   net::HttpByteRange byte_range_;
 
   DISALLOW_COPY_AND_ASSIGN(FileSystemURLRequestJob);
 };
 
 }  // namespace fileapi
 
 #endif  // WEBKIT_FILEAPI_FILE_SYSTEM_URL_REQUEST_JOB_H_