Adding Angular and dependent packages for testing

third_party/pkg/angular/lib/directive/ng_bind_template.dart

+part of angular.directive;
+
+/**
+ * The [NgBindTemplateDirective] specifies that the element text content should be replaced with
+ * the interpolation of the template in the ngBindTemplate attribute. Unlike ngBind, the
+ * ngBindTemplate can contain multiple {{ }} expressions.
+ */
+@NgDirective(
+  selector: '[ng-bind-template]',
+  map: const {'ng-bind-template': '@bind'})
+class NgBindTemplateDirective {
+  dom.Element element;
+
+  NgBindTemplateDirective(this.element);
+
+  set bind(value) {
+    element.text = value;
+  }
+}