Do not poison %FunctionPrototype%'s restricted properties

chrome/test/data/extensions/api_test/messaging/externally_connectable/sites/assertions.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.
 
 (function() {
 
 // We are going to kill all of the builtins, so hold onto the ones we need.
 var defineGetter = Object.prototype.__defineGetter__;
 var defineSetter = Object.prototype.__defineSetter__;
 var Error = window.Error;
@@ skipping 11 matching lines @@
 ];
 
 function clobber(obj, name, qualifiedName) {
   // Clobbering constructors would break everything.
   // Clobbering toString is annoying.
   // Clobbering __proto__ breaks in ways that grep can't find.
   // Clobbering function name will break because
   // SafeBuiltins does not support getters yet. See crbug.com/463526.
   // Clobbering Function.call would make it impossible to implement these tests.
   // Clobbering Object.valueOf breaks v8.
+  // Clobbering %FunctionPrototype%.caller and .arguments will break because
+  // these properties are poisoned accessors in ES6.
   if (name == 'constructor' ||
       name == 'toString' ||
       name == '__proto__' ||
       name == 'name' && typeof obj == 'function' ||
       qualifiedName == 'Function.call' ||
+      (obj !== Function && qualifiedName == 'Function.caller') ||
+      (obj !== Function && qualifiedName == 'Function.arguments') ||
       qualifiedName == 'Object.valueOf') {
     return;
   }
   if (typeof obj[name] == 'function') {
     obj[name] = function() {
       throw new Error('Clobbered ' + qualifiedName + ' function');
     };
   } else {
     defineGetter.call(obj, name, function() {
       throw new Error('Clobbered ' + qualifiedName + ' getter');
@@ skipping 247 matching lines @@
     if (!message)
       message = kMessage;
 
     chrome.runtime.sendMessage(extensionId, message,
         {'includeTlsChannelId': includeTlsChannelId},
         checkTlsChannelIdResponse);
   }
 };
 
 }());