Allow omitting optional parameters for Extensions API functions

chrome/renderer/resources/extensions/tabs_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 tabs API.
 
 (function() {
 
 native function GetChromeHidden();
 native function OpenChannelToTab();
@@ skipping 25 matching lines @@
     port.onMessage.addListener(function(response) {
       try {
         if (responseCallback)
           responseCallback(response);
       } finally {
         port.disconnect();
         port = null;
       }
     });
   });
-
-  // TODO(skerner,mtytel): The next step to omitting optional arguments is the
-  // replacement of this code with code that matches arguments by type.
-  // Once this is working for captureVisibleTab() it can be enabled for
-  // the rest of the API. See crbug/29215 .
-  apiFunctions.setUpdateArgumentsPreValidate('captureVisibleTab', function() {
-    // Old signature:
-    //    captureVisibleTab(int windowId, function callback);
-    // New signature:
-    //    captureVisibleTab(int windowId, object details, function callback);
-    var newArgs;
-    if (arguments.length == 2 && typeof(arguments[1]) == 'function') {
-      // If the old signature is used, add a null details object.
-      newArgs = [arguments[0], null, arguments[1]];
-    } else {
-      newArgs = arguments;
-    }
-    return newArgs;
-  });
 });
 
 })();