Adding Angular and dependent packages for testing

third_party/pkg/angular/lib/core_dom/common.dart

+part of angular.core.dom;
+
+List<dom.Node> cloneElements(elements) {
+  var clones = [];
+  for(var i = 0, ii = elements.length; i < ii; i++) {
+    clones.add(elements[i].clone(true));
+  }
+  return clones;
+}
+
+typedef ApplyMapping(NodeAttrs attrs, Scope scope, Object dst);
+
+class DirectiveRef {
+  final dom.Node element;
+  final Type type;
+  final NgAnnotation annotation;
+  final String value;
+  final List<ApplyMapping> mappings = new List<ApplyMapping>();
+
+  BlockFactory blockFactory;
+
+  DirectiveRef(this.element, this.type, this.annotation, [ this.value ]);
+
+  String toString() {
+    var html = element is dom.Element ? (element as dom.Element).outerHtml : element.nodeValue;
+    return '{ element: $html, selector: ${annotation.selector}, value: $value }';
+  }
+}
+