Allow omitting optional parameters for Extensions API functions

chrome/renderer/resources/extensions/windows_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 bindings for the windows API.
-
-(function() {
-
-native function GetChromeHidden();
-
-GetChromeHidden().registerCustomHook('windows', function(api) {
-  var apiFunctions = api.apiFunctions;
-
-  apiFunctions.setUpdateArgumentsPreValidate('get', function() {
-    // Old signature:
-    //    get(int windowId, function callback);
-    // New signature:
-    //    get(int windowId, object populate, function callback);
-    if (arguments.length == 2 && typeof(arguments[1]) == 'function') {
-      // If the old signature is used, add a null populate object.
-      newArgs = [arguments[0], null, arguments[1]];
-    } else {
-      newArgs = arguments;
-    }
-    return newArgs;
-  });
-
-  apiFunctions.setUpdateArgumentsPreValidate('getCurrent', function() {
-    // Old signature:
-    //    getCurrent(function callback);
-    // New signature:
-    //    getCurrent(object populate, function callback);
-    if (arguments.length == 1 && typeof(arguments[0]) == 'function') {
-      // If the old signature is used, add a null populate object.
-      newArgs = [null, arguments[0]];
-    } else {
-      newArgs = arguments;
-    }
-    return newArgs;
-  });
-
-  apiFunctions.setUpdateArgumentsPreValidate('getLastFocused', function() {
-    // Old signature:
-    //    getLastFocused(function callback);
-    // New signature:
-    //    getLastFocused(object populate, function callback);
-    if (arguments.length == 1 && typeof(arguments[0]) == 'function') {
-      // If the old signature is used, add a null populate object.
-      newArgs = [null, arguments[0]];
-    } else {
-      newArgs = arguments;
-    }
-    return newArgs;
-  });
-
-  apiFunctions.setUpdateArgumentsPreValidate('getAll', function() {
-    // Old signature:
-    //    getAll(function callback);
-    // New signature:
-    //    getAll(object populate, function callback);
-    if (arguments.length == 1 && typeof(arguments[0]) == 'function') {
-      // If the old signature is used, add a null populate object.
-      newArgs = [null, arguments[0]];
-    } else {
-      newArgs = arguments;
-    }
-    return newArgs;
-  });
-});
-
-})();