Make arguments to Location.assign() and .replace() non-optional

Source/core/frame/Location.idl

 /*
  * Copyright (C) 2008 Apple Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 18 matching lines @@
 [
     CheckSecurity=Frame,
 ] interface Location {
     // |assign|, |replace|, and *writing* |href| do not require a security
     // check, as they *change* the page, and thus these do not change any
     // property of an *existing* document at a different origin.
     // However, *reading* |href|, or accessing any component, is a security
     // problem, since that allows tracking navigation.
     [SetterCallWith=ActiveWindow&FirstWindow, DoNotCheckSecurity=Setter, Unforgeable] attribute DOMString href;
 
-    [CallWith=ActiveWindow&FirstWindow, DoNotCheckSecurity, Unforgeable, ReadOnly, PerWorldBindings, ActivityLogging=ForIsolatedWorlds] void assign([Default=Undefined] optional DOMString url);
-    [CallWith=ActiveWindow&FirstWindow, DoNotCheckSecurity, Unforgeable, ReadOnly, PerWorldBindings, ActivityLogging=ForIsolatedWorlds] void replace([Default=Undefined] optional DOMString url);
+    [CallWith=ActiveWindow&FirstWindow, DoNotCheckSecurity, Unforgeable, ReadOnly, PerWorldBindings, ActivityLogging=ForIsolatedWorlds] void assign(DOMString url);
+    [CallWith=ActiveWindow&FirstWindow, DoNotCheckSecurity, Unforgeable, ReadOnly, PerWorldBindings, ActivityLogging=ForIsolatedWorlds] void replace(DOMString url);
     [CallWith=ActiveWindow, Unforgeable, ReadOnly] void reload();
 
     // URI decomposition attributes
     [SetterCallWith=ActiveWindow&FirstWindow, RaisesException=Setter] attribute DOMString protocol;
     [SetterCallWith=ActiveWindow&FirstWindow] attribute DOMString host;
     [SetterCallWith=ActiveWindow&FirstWindow] attribute DOMString hostname;
     [SetterCallWith=ActiveWindow&FirstWindow] attribute DOMString port;
     [SetterCallWith=ActiveWindow&FirstWindow] attribute DOMString pathname;
     [SetterCallWith=ActiveWindow&FirstWindow] attribute DOMString search;
     [SetterCallWith=ActiveWindow&FirstWindow] attribute DOMString hash;
 
     readonly attribute DOMString origin;
 
     readonly attribute DOMStringList ancestorOrigins;
 
     [NotEnumerable, Unforgeable, ReadOnly, ImplementedAs=href] DOMString toString();
     [NotEnumerable, Custom, Unforgeable, ReadOnly] any valueOf();
 };