Revive tests for Document.createAttributeNS() and Element.setAttributeNodeNS()

LayoutTests/fast/css/lang-mapped-to-webkit-locale-dynamic.xhtml

Index: LayoutTests/fast/css/lang-mapped-to-webkit-locale-dynamic.xhtml
diff --git a/LayoutTests/fast/css/lang-mapped-to-webkit-locale-dynamic.xhtml b/LayoutTests/fast/css/lang-mapped-to-webkit-locale-dynamic.xhtml
index a80e96a74df9ab7bc2ea21cf39f678dfa003407e..3d89d9d8b8135773d4b74be9653c9d19a963a1f6 100644
--- a/LayoutTests/fast/css/lang-mapped-to-webkit-locale-dynamic.xhtml
+++ b/LayoutTests/fast/css/lang-mapped-to-webkit-locale-dynamic.xhtml
@@ -31,6 +31,21 @@ function runTest() {
     x3.removeAttribute("lang");
     shouldBeEqualToString("localeOfNode('x3')", "ja");
 
+    // The "lang" attribute in the XML namespace should affect locale (since this is an XHTML document).
+    var attr1 = document.createAttributeNS("http://www.w3.org/XML/1998/namespace", "xml:lang");
+    attr1.value = "zh";
+    x2.setAttributeNodeNS(attr1);
+    shouldBeEqualToString("localeOfNode('x2')", "zh");
+
+    x2.removeAttributeNode(attr1);
+    shouldBeEqualToString("localeOfNode('x2')", "ja");
+
+    // An attribute with local name "lang" not in the XML namespace should not affect locale.
+    var attr2 = document.createAttributeNS("foobar", "fb:lang");
+    attr2.value = "ph";
+    x2.setAttributeNodeNS(attr2);
+    shouldBeEqualToString("localeOfNode('x2')", "ja");
+
     // If we include js-test-post.js directly, the "TEST COMPLETE" output comes out of order.
     wasPostTestScriptParsed = true;
     finishJSTest();