Adding Angular and dependent packages for testing

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

+part of angular.directive;
+
+/**
+ * The ngHide directive shows or hides the given HTML element based on the
+ * expression provided to the ngHide attribute. The element is shown or hidden
+ * by changing the removing or adding the ng-hide CSS class onto the element.
+ */
+@NgDirective(
+    selector: '[ng-hide]',
+    map: const {'ng-hide': '=>hide'} )
+class NgHideDirective {
+  static String NG_HIDE_CLASS = 'ng-hide';
+
+  dom.Element element;
+
+  NgHideDirective(this.element);
+
+  set hide(value) {
+    if (toBool(value)) {
+      element.classes.add(NG_HIDE_CLASS);
+    } else {
+      element.classes.remove(NG_HIDE_CLASS);
+    }
+  }
+}
+
+/**
+ * The ngShow directive shows or hides the given HTML element based on the
+ * expression provided to the ngHide attribute. The element is shown or hidden
+ * by changing the removing or adding the ng-hide CSS class onto the element.
+ */
+@NgDirective(
+    selector: '[ng-show]',
+    map: const {'ng-show': '=>show'})
+class NgShowDirective {
+  static String NG_SHOW_CLASS = 'ng-show';
+
+  dom.Element element;
+
+  NgShowDirective(this.element);
+
+  set show(value) {
+    if (toBool(value)) {
+      element.classes.add(NG_SHOW_CLASS);
+    } else {
+      element.classes.remove(NG_SHOW_CLASS);
+    }
+  }
+}
+