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

webkit/chromeos/fileapi/cros_mount_point_provider.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_CHROMEOS_FILEAPI_CROS_MOUNT_POINT_PROVIDER_H_
 #define WEBKIT_CHROMEOS_FILEAPI_CROS_MOUNT_POINT_PROVIDER_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 51 matching lines @@
   virtual std::vector<FilePath> GetRootDirectories() const OVERRIDE;
   virtual fileapi::FileSystemFileUtil* GetFileUtil() OVERRIDE;
   virtual FilePath GetPathForPermissionsCheck(const FilePath& virtual_path)
       const OVERRIDE;
   virtual fileapi::FileSystemOperationInterface* CreateFileSystemOperation(
       const GURL& origin_url,
       fileapi::FileSystemType file_system_type,
       const FilePath& virtual_path,
       base::MessageLoopProxy* file_proxy,
       fileapi::FileSystemContext* context) const OVERRIDE;
+  virtual webkit_blob::FileReader* CreateFileReader(
+    const GURL& path,
+    int64 offset,
+    base::MessageLoopProxy* file_proxy,
+    fileapi::FileSystemContext* context) const OVERRIDE;
 
   // fileapi::ExternalFileSystemMountPointProvider overrides.
   virtual void GrantFullAccessToExtension(
       const std::string& extension_id) OVERRIDE;
   virtual void GrantFileAccessToExtension(
       const std::string& extension_id, const FilePath& virtual_path) OVERRIDE;
   virtual void RevokeAccessForExtension(
       const std::string& extension_id) OVERRIDE;
   virtual bool HasMountPoint(const FilePath& mount_point) OVERRIDE;
   virtual void AddLocalMountPoint(const FilePath& mount_point) OVERRIDE;
@@ skipping 42 matching lines @@
   MountPointMap mount_point_map_;
   scoped_refptr<quota::SpecialStoragePolicy> special_storage_policy_;
   scoped_ptr<FileAccessPermissions> file_access_permissions_;
   scoped_ptr<fileapi::LocalFileUtil> local_file_util_;
   DISALLOW_COPY_AND_ASSIGN(CrosMountPointProvider);
 };
 
 }  // namespace chromeos
 
 #endif  // WEBKIT_CHROMEOS_FILEAPI_CROS_MOUNT_POINT_PROVIDER_H_