IDL: make optional arguments (without default) explicit sometimes

Source/core/xml/XPathEvaluator.idl

Index: Source/core/xml/XPathEvaluator.idl
diff --git a/Source/core/xml/XPathEvaluator.idl b/Source/core/xml/XPathEvaluator.idl
index d11018a46e80a9e45cedf4ee8d2f97d3c6a15213..c435382c2916ceb6ee25a717ae2e916ab5a0f0ac 100644
--- a/Source/core/xml/XPathEvaluator.idl
+++ b/Source/core/xml/XPathEvaluator.idl
@@ -21,14 +21,14 @@
     WillBeGarbageCollected,
     Constructor
 ] interface XPathEvaluator {
-    [RaisesException] XPathExpression createExpression([Default=Undefined] optional DOMString expression,
-                                     [Default=Undefined] optional XPathNSResolver resolver);
+    [RaisesException] XPathExpression createExpression(optional DOMString expression,
+                                     optional XPathNSResolver resolver);
 
-    XPathNSResolver createNSResolver([Default=Undefined] optional Node nodeResolver);
+    XPathNSResolver createNSResolver(optional Node nodeResolver);
 
-    [RaisesException] XPathResult evaluate([Default=Undefined] optional DOMString expression,
-                         [Default=Undefined] optional Node contextNode,
-                         [Default=Undefined] optional XPathNSResolver resolver,
-                         [Default=Undefined] optional unsigned short type,
-                         [Default=Undefined] optional XPathResult inResult);
+    [RaisesException] XPathResult evaluate(optional DOMString expression,
+                         optional Node contextNode,
+                         optional XPathNSResolver resolver,
+                         optional unsigned short type,
+                         optional XPathResult inResult);
 };