Add [TypeChecking=Interface] to XPath interfaces

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..7a69a5b53a8519eb71e8e6c0d61e1268d175ed1e 100644
--- a/Source/core/xml/XPathEvaluator.idl
+++ b/Source/core/xml/XPathEvaluator.idl
@@ -19,16 +19,12 @@
 
 [
     WillBeGarbageCollected,
-    Constructor
+    Constructor,
+    TypeChecking=Interface,
 ] interface XPathEvaluator {
-    [RaisesException] XPathExpression createExpression([Default=Undefined] optional DOMString expression,
-                                     [Default=Undefined] optional XPathNSResolver resolver);
+    [RaisesException] XPathExpression createExpression(DOMString expression, XPathNSResolver? resolver);

[philipj_slow, 2015/03/06 15:53:13]

I think "optional XPathNSResolver? resolver = null"

 
-    XPathNSResolver createNSResolver([Default=Undefined] optional Node nodeResolver);
+    XPathNSResolver createNSResolver(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(DOMString expression, Node contextNode, XPathNSResolver? resolver, unsigned short type, object? inResult);

[philipj_slow, 2015/03/06 15:53:13]

resolver and the following can be optional with default values I think. Not
contextNode, because that would currently throw in the C++ code.

 };