Convert legacy 'native code' to JS-forms in dart:html

lib/html/templates/html/dart2js/factoryprovider_OptionElement.darttemplate

Index: lib/html/templates/html/dart2js/factoryprovider_OptionElement.darttemplate
diff --git a/lib/html/templates/html/dart2js/factoryprovider_OptionElement.darttemplate b/lib/html/templates/html/dart2js/factoryprovider_OptionElement.darttemplate
index 0c8ce95508c3a45de79a6eb2730daa44ddf3076d..22769d8405083958b653f94ceeeccb4c425c6160 100644
--- a/lib/html/templates/html/dart2js/factoryprovider_OptionElement.darttemplate
+++ b/lib/html/templates/html/dart2js/factoryprovider_OptionElement.darttemplate
@@ -4,12 +4,21 @@
 
 class $FACTORYPROVIDER {
   static OptionElement createOptionElement(
-      [String data, String value, bool defaultSelected, bool selected])
-      native '''
-          if (data == null) return new Option();
-          if (value == null) return new Option(data);
-          if (defaultSelected == null) return new Option(data, value);
-          if (selected == null) return new Option(data, value, defaultSelected);
-          return new Option(data, value, defaultSelected, selected);
-      ''';
+      [String data, String value, bool defaultSelected, bool selected]) {
+    if (data == null) {
+      return JS('OptionElement', 'new Option()');
+    }
+    if (value == null) {
+      return JS('OptionElement', 'new Option(#)', data);
+    }
+    if (defaultSelected == null) {
+      return JS('OptionElement', 'new Option(#,#)', data, value);
+    }
+    if (selected == null) {
+      return JS('OptionElement', 'new Option(#,#,#)',
+                data, value, defaultSelected);
+    }
+    return JS('OptionElement', 'new Option(#,#,#,#)',
+              data, value, defaultSelected, selected);
+  }
 }