dart:html perf optimization based on runing Dromaeo benchmarks

samples/third_party/dromaeo/tests/dom-attr-html.dart

Index: samples/third_party/dromaeo/tests/dom-attr-html.dart
diff --git a/samples/third_party/dromaeo/tests/dom-attr-html.dart b/samples/third_party/dromaeo/tests/dom-attr-html.dart
index ba3c11d7072067149b66f2ffc7af5917516e6377..653a84d07aa8d5a0baa7b62bd025518a8cb34d4c 100644
--- a/samples/third_party/dromaeo/tests/dom-attr-html.dart
+++ b/samples/third_party/dromaeo/tests/dom-attr-html.dart
@@ -1,8 +1,6 @@
-#library("dom_attr_html");
+#library("dom_attr");
 #import("dart:html");
-#import("dart:json");
-#source("Common.dart");
-#source("RunnerSuite.dart");
+#import('runner.dart');
 
 void main() {
   final int num = 10240;
@@ -11,12 +9,12 @@ void main() {
   var ret;
 
   Element elem = document.query('#test1');
-  Element a = document.queryAll('a')[0];
+  Element a = document.query('a');
 
   new Suite(window, 'dom-attr')
     .test('getAttribute', () {
       for (int i = 0; i < num; i++)
-        ret = elem.attributes['id'];
+        ret = elem.$dom_getAttribute('id');
     })
     .test('element.property', () {
       for (int i = 0; i < num * 2; i++)
@@ -24,7 +22,7 @@ void main() {
     })
     .test('setAttribute', () {
         for (int i = 0; i < num; i++)
-        a.attributes['id'] = 'foo';
+        a.$dom_setAttribute('id', 'foo');
     })
     .test('element.property = value', () {
       for (int i = 0; i < num; i++)