Replace createTextNode with new Text().

sky/tests/mutation-observer/mutation-record-nullity.sky

Index: sky/tests/mutation-observer/mutation-record-nullity.sky
diff --git a/sky/tests/mutation-observer/mutation-record-nullity.sky b/sky/tests/mutation-observer/mutation-record-nullity.sky
index f32da6409278b540bf348698cf97bf35051368ae..a3dfe00380bd8e2a75c64f0671e114dc79e87de2 100644
--- a/sky/tests/mutation-observer/mutation-record-nullity.sky
+++ b/sky/tests/mutation-observer/mutation-record-nullity.sky
@@ -7,7 +7,7 @@ describe('Non-relevant properties on mutation records should be null, except for
   var observer = new MutationObserver(function() {});
 
   it('on characterData records', function() {
-    var text = document.createTextNode('something');
+    var text = new Text('something');
     observer.observe(text, {characterData: true});
     text.data = 'something else';
     var record = observer.takeRecords()[0];