Lint fix.

test/unit/legacy-noattributes.html

@@ -81,7 +81,7 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
         properties: {
           tabindex: {reflectToAttribute: true, type: Number}
         },
-        attributeChanged(name, old, value) {
+        attributeChanged() {
           this.attributeChangedCalled = true;
         }
       });