dart:html perf optimization based on runing Dromaeo benchmarks

samples/third_party/dromaeo/tests/dom-query-htmlidiomatic.dart

 #library("dom_query_html");
 #import("dart:html");
 #import('../common/common.dart');
 #source("Common.dart");
 #source("RunnerSuite.dart");
 
 void main() {
   final int num = 40;
 
   // Try to force real results.
@@ skipping 12 matching lines @@
       });
       html = BenchUtil.replaceAll(html, 'class="foo.*?"', (Match match) {
         return 'class="foo test${num} bar"';
       });
       final div = new Element.tag('div');
       div.innerHTML = html;
       document.body.nodes.add(div);
     })
     .test('getElementById', () {
       for (int i = 0; i < num * 30; i++) {
-        ret = document.query('#testA$num').hidden;
-        ret = document.query('#testB$num').hidden;
-        ret = document.query('#testC$num').hidden;
-        ret = document.query('#testD$num').hidden;
-        ret = document.query('#testE$num').hidden;
-        ret = document.query('#testF$num').hidden;
+        ret = document.query('#testA$num').$dom_nodeType;
+        ret = document.query('#testB$num').$dom_nodeType;
+        ret = document.query('#testC$num').$dom_nodeType;
+        ret = document.query('#testD$num').$dom_nodeType;
+        ret = document.query('#testE$num').$dom_nodeType;
+        ret = document.query('#testF$num').$dom_nodeType;
       }
     })
     .test('getElementById (not in document)', () {
       for (int i = 0; i < num * 30; i++) {
         ret = document.query('#testA');
         ret = document.query('#testB');
         ret = document.query('#testC');
         ret = document.query('#testD');
         ret = document.query('#testE');
         ret = document.query('#testF');
       }
     })
     .test('getElementsByTagName(div)', () {
       for (int i = 0; i < num; i++) {
-        var elems = document.queryAll('div');
-        ret = elems.last().hidden;
+        final elems = document.queryAll('div');
+        ret = elems.last().$dom_nodeType;
       }
     })
     .test('getElementsByTagName(p)', () {
       for (int i = 0; i < num; i++) {
         final elems = document.queryAll('p');
-        ret = elems.last().hidden;
+        ret = elems.last().$dom_nodeType;
       }
     })
     .test('getElementsByTagName(a)', () {
       for (int i = 0; i < num; i++) {
-        var elems = document.queryAll('a');
-        ret = elems.last().hidden;
+        final elems = document.queryAll('a');
+        ret = elems.last().$dom_nodeType;
       }
     })
     .test('getElementsByTagName(*)', () {
       for (int i = 0; i < num; i++) {
-        var elems = document.queryAll('*');
-        ret = elems.last().hidden;
+        final elems = document.queryAll('*');
+        ret = elems.last().$dom_nodeType;
       }
     })
     .test('getElementsByTagName (not in document)', () {
       for (int i = 0; i < num; i++) {
-        var elems = document.queryAll('strong');
-        ret = elems.length == 0;
+        final elems = document.queryAll('strong');
+        ret = elems.last().$dom_nodeType;
       }
     })
     .test('getElementsByName', () {
       for (int i = 0; i < num * 20; i++) {
-        var elems = document.queryAll('[name="test$num"]');
-        ret = elems.last().hidden;
+        ElementList elems = document.queryAll('[name="test$num"]');
+        ret = elems.last().$dom_nodeType;
         elems = document.queryAll('[name="test$num"]');
-        ret = elems.last().hidden;
+        ret = elems.last().$dom_nodeType;
         elems = document.queryAll('[name="test$num"]');
-        ret = elems.last().hidden;
+        ret = elems.last().$dom_nodeType;
         elems = document.queryAll('[name="test$num"]');
-        ret = elems.last().hidden;
+        ret = elems.last().$dom_nodeType;
       }
     })
     .test('getElementsByName (not in document)', () {
       for (int i = 0; i < num * 20; i++) {
         ret = document.queryAll('[name="test"]').length == 0;
         ret = document.queryAll('[name="test"]').length == 0;
         ret = document.queryAll('[name="test"]').length == 0;
         ret = document.queryAll('[name="test"]').length == 0;
         ret = document.queryAll('[name="test"]').length == 0;
       }
     })
     .end();
 }