Add FileReader interface and implement FileSystemFileReader

webkit/fileapi/webkit_fileapi.gypi

 # 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.
 
 {
   'targets': [
     {
       'target_name': 'fileapi',
       'type': 'static_library',
       'variables': { 'enable_wexit_time_destructors': 1, },
       'dependencies': [
         '<(DEPTH)/base/base.gyp:base',
         '<(DEPTH)/net/net.gyp:net',
         '<(DEPTH)/third_party/leveldatabase/leveldatabase.gyp:leveldatabase',
         '<(DEPTH)/webkit/support/webkit_support.gyp:quota',
       ],
       'sources': [
         'file_system_callback_dispatcher.cc',
         'file_system_callback_dispatcher.h',
         'file_system_context.cc',
         'file_system_context.h',
         'file_system_dir_url_request_job.cc',
         'file_system_dir_url_request_job.h',
         'file_system_directory_database.cc',
         'file_system_directory_database.h',
+        'file_system_file_reader.cc',
+        'file_system_file_reader.h',
         'file_system_file_util.cc',
         'file_system_file_util.h',
         'file_system_file_util_proxy.cc',
         'file_system_file_util_proxy.h',
         'file_system_mount_point_provider.h',
         'file_system_operation.cc',
         'file_system_operation.h',
         'file_system_operation_context.cc',
         'file_system_operation_context.h',
         'file_system_operation_interface.h',
@@ skipping 55 matching lines @@
             '../chromeos/fileapi/file_util_async.h',
             '../chromeos/fileapi/remote_file_system_operation.cc',
             '../chromeos/fileapi/remote_file_system_operation.h',
             '../chromeos/fileapi/remote_file_system_proxy.h',
           ],
         }],
       ],
     },
   ],
 }