Lazily require types when validating Extensions API calls

chrome/renderer/resources/extensions/storage_custom_bindings.js

-// 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.
-
-// Custom binding for the storage API.
-
-var binding = require('binding').Binding.create('storage');
-
-var forEach = require('utils').forEach;
-var normalizeArgumentsAndValidate =
-    require('schemaUtils').normalizeArgumentsAndValidate
-var sendRequest = require('sendRequest').sendRequest;
-
-binding.registerCustomType('storage.StorageArea', function() {
-  function extendSchema(schema) {
-    var extendedSchema = schema.slice();
-    extendedSchema.unshift({'type': 'string'});
-    return extendedSchema;
-  }
-
-  function StorageArea(namespace, schema) {
-    // Binds an API function for a namespace to its browser-side call, e.g.
-    // storage.sync.get('foo') -> (binds to) ->
-    // storage.get('sync', 'foo').
-    //
-    // TODO(kalman): Put as a method on CustombindingObject and re-use (or
-    // even generate) for other APIs that need to do this. Same for other
-    // callers of registerCustomType().
-    var self = this;
-    function bindApiFunction(i, functionName) {
-      self[functionName] = function() {
-        var funSchema = this.functionSchemas[functionName];
-        var args = Array.prototype.slice.call(arguments);
-        args = normalizeArgumentsAndValidate(args, funSchema);
-        return sendRequest(
-            'storage.' + functionName,
-            [namespace].concat(args),
-            extendSchema(funSchema.definition.parameters),
-            {preserveNullInObjects: true});
-      };
-    }
-    var apiFunctions = ['get', 'set', 'remove', 'clear', 'getBytesInUse'];
-    forEach(apiFunctions, bindApiFunction);
-  }
-
-  return StorageArea;
-});
-
-exports.binding = binding.generate();