Remove support for attribute event listeners.

client/dom/benchmarks/dromaeo/tests/dom-modify.dart

 #library("dom-modify.dart");
 #import("dart:dom");
 #import('runner.dart');
 
 void main() {
   final int num = 400;
 
   String str = 'null';
   // Very ugly way to build up the string, but let's mimic JS version as much as possible.
   for (int i = 0; i < 1024; i++) {
     str += new String.fromCharCodes([((25 * Math.random()) + 97).toInt()]);
   }
 
   List<Node> elems = new List<Node>();
 
   // Try to force real results.
   var ret;
-  window.onload = (Event evt) {
-    final htmlstr = document.body.innerHTML;
 
-    new Suite(window, 'dom-modify')
-      .test('createElement', () {
-        for (int i = 0; i < num; i++) {
-          ret = document.createElement('div');
-          ret = document.createElement('span');
-          ret = document.createElement('table');
-          ret = document.createElement('tr');
-          ret = document.createElement('select');
+  final htmlstr = document.body.innerHTML;
+
+  new Suite(window, 'dom-modify')
+    .test('createElement', () {
+      for (int i = 0; i < num; i++) {
+        ret = document.createElement('div');
+        ret = document.createElement('span');
+        ret = document.createElement('table');
+        ret = document.createElement('tr');
+        ret = document.createElement('select');
+      }
+    })
+    .test('createTextNode', () {
+      for (int i = 0; i < num; i++) {
+        ret = document.createTextNode(str);
+        ret = document.createTextNode(str + '2');
+        ret = document.createTextNode(str + '3');
+        ret = document.createTextNode(str + '4');
+        ret = document.createTextNode(str + '5');
+      }
+    })
+    .test('innerHTML', () {
+      document.body.innerHTML = htmlstr;
+    })
+    .prep(() {
+      elems = new List<Node>();
+      final telems = document.body.childNodes;
+      for (int i = 0; i < telems.length; i++) {
+        elems.add(telems[i]);
+      }
+    })
+    .test('cloneNode', () {
+      for (int i = 0; i < elems.length; i++) {
+        ret = elems[i].cloneNode(false);
+        ret = elems[i].cloneNode(true);
+        ret = elems[i].cloneNode(true);
         }
-      })
-      .test('createTextNode', () {
-        for (int i = 0; i < num; i++) {
-          ret = document.createTextNode(str);
-          ret = document.createTextNode(str + '2');
-          ret = document.createTextNode(str + '3');
-          ret = document.createTextNode(str + '4');
-          ret = document.createTextNode(str + '5');
-        }
-      })
-      .test('innerHTML', () {
-        document.body.innerHTML = htmlstr;
-      })
-      .prep(() {
-        elems = new List<Node>();
-        final telems = document.body.childNodes;
-        for (int i = 0; i < telems.length; i++) {
-          elems.add(telems[i]);
-        }
-      })
-      .test('cloneNode', () {
-        for (int i = 0; i < elems.length; i++) {
-          ret = elems[i].cloneNode(false);
-          ret = elems[i].cloneNode(true);
-          ret = elems[i].cloneNode(true);
-          }
-      })
-      .test('appendChild', () {
-        for (int i = 0; i < elems.length; i++)
-          document.body.appendChild(elems[i]);
-      })
-      .test('insertBefore', () {
-        for (int i = 0; i < elems.length; i++)
-          document.body.insertBefore(elems[i], document.body.firstChild);
-      })
-      .end();
-  };
+    })
+    .test('appendChild', () {
+      for (int i = 0; i < elems.length; i++)
+        document.body.appendChild(elems[i]);
+    })
+    .test('insertBefore', () {
+      for (int i = 0; i < elems.length; i++)
+        document.body.insertBefore(elems[i], document.body.firstChild);
+    })
+    .end();
 }