[fsp] Add FileStreamReader for the reading operation.

chrome/renderer/resources/extensions/file_system_provider_custom_bindings.js

 // Copyright 2013 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.
 
 // Custom binding for the fileSystemProvider API.
 
 var binding = require('binding').Binding.create('fileSystemProvider');
 var fileSystemProviderInternal =
     require('binding').Binding.create('fileSystemProviderInternal').generate();
 var eventBindings = require('event_bindings');
@@ skipping 177 matching lines @@
       var requestId = args[1];
       var openRequestId = args[2];
       var onSuccessCallback = function() {
         fileSystemProviderInternal.closeFileRequestedSuccess(
             fileSystemId, requestId);
       };
       var onErrorCallback = function(error) {
         fileSystemProviderInternal.closeFileRequestedError(
           fileSystemId, requestId, error);
       }
-      dispatch([fileSystemId, openRequestId, openRequestId, onSuccessCallback,
-                onErrorCallback]);
+      dispatch([fileSystemId, openRequestId, onSuccessCallback,
+          onErrorCallback]);
     });
 
 eventBindings.registerArgumentMassager(
     'fileSystemProvider.onReadFileRequested',
     function(args, dispatch) {
       var fileSystemId = args[0];
       var requestId = args[1];
       var openRequestId = args[2];
       var offset = args[3];
       var length = args[4];
       var onSuccessCallback = function(data, hasNext) {
         fileSystemProviderInternal.readFileRequestedSuccess(
             fileSystemId, requestId, data, hasNext);
       };
       var onErrorCallback = function(error) {
         fileSystemProviderInternal.readFileRequestedError(
           fileSystemId, requestId, error);
       }
       dispatch([fileSystemId, openRequestId, offset, length, onSuccessCallback,
                 onErrorCallback]);
     });
 
 exports.binding = binding.generate();