Sync XML-related interfaces with their specs, or lack thereof

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 3e92523ed2b38a4e6f3af39d5fa707928dc6609b..70f258fce99998e5d5fd947e7e72da20deb91952 100644
--- a/Source/core/xml/XPathEvaluator.idl
+++ b/Source/core/xml/XPathEvaluator.idl
@@ -17,14 +17,23 @@
  * Boston, MA 02110-1301, USA.
  */
 
+// http://www.w3.org/TR/DOM-Level-3-XPath/xpath.html#XPathEvaluator
+
+// Note: The spec says "the XPathEvaluator interface will be implemented on the
+// same object which implements the Document interface" and does not define a
+// constructor or other means to create an XPathEvaluator object. Nonetheless,
+// Blink, Gecko, Presto, WebKit and all have these APIs on both Document and the
+// constructable XPathEvaluator interface.
+
 [
     Constructor,
     GarbageCollected,
+    Measure,
     TypeChecking=Interface,
 ] interface XPathEvaluator {
-    [RaisesException] XPathExpression createExpression(DOMString expression, optional XPathNSResolver? resolver = null);
+    [Measure, RaisesException] XPathExpression createExpression(DOMString expression, optional XPathNSResolver? resolver = null);
 
-    XPathNSResolver createNSResolver(Node nodeResolver);
+    [Measure] XPathNSResolver createNSResolver(Node nodeResolver);
 
-    [RaisesException] XPathResult evaluate(DOMString expression, Node contextNode, optional XPathNSResolver? resolver = null, optional unsigned short type = 0, optional object? inResult = null);
+    [Measure, RaisesException] XPathResult evaluate(DOMString expression, Node contextNode, optional XPathNSResolver? resolver = null, optional unsigned short type = 0, optional object? inResult = null);
 };