Remove obsolete version of dromaeo

lib/html/benchmarks/dromaeo/tests/DomModify.dart

-class Main {
-  static 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()]);
-    }
-
-    Array<Node> elems = new Array<Node>();
-
-    // Try to force real results.
-    var ret;
-    window.on.load.add((Event evt) {
-      final htmlstr = document.body.innerHTML;
-
-      new Suite('dom-modify')
-        .test('createElement', () {
-          for (int i = 0; i < num; i++) {
-            ret = new Element.tag('div');
-            ret = new Element.tag('span');
-            ret = new Element.tag('table');
-            ret = new Element.tag('tr');
-            ret = new Element.tag('select');
-          }
-        })
-        .test('createTextNode', () {
-          for (int i = 0; i < num; i++) {
-            ret = new Text(str);
-            ret = new Text(str + '2');
-            ret = new Text(str + '3');
-            ret = new Text(str + '4');
-            ret = new Text(str + '5');
-          }
-        })
-        .test('innerHTML', () {
-          document.body.innerHTML = htmlstr;
-        })
-        .prep(() {
-          elems = new Array<Node>();
-          final telems = document.body.nodes;
-          for (int i = 0; i < telems.length; i++) {
-            elems.add(telems[i]);
-          }
-        })
-        .test('clone', () {
-          for (int i = 0; i < elems.length; i++) {
-            // not supported by Dart... this will intentionally throw an exception.
-            // TODO(jacobr): find the right solution.
-            ret = elems[i].dynamic.clone(false);
-            ret = elems[i].dynamic.clone(true);
-            ret = elems[i].dynamic.clone(true);
-          }
-        })
-        .test('appendChild', () {
-          for (int i = 0; i < elems.length; i++)
-            document.body.nodes.add(elems[i]);
-        })
-        .test('insertBefore', () {
-          for (int i = 0; i < elems.length; i++)
-            document.body.insertBefore(elems[i], document.body.nodes.first);
-        })
-        .end();
-    });
-  }
-}