Adding Angular and dependent packages for testing

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

+part of angular.directive;
+
+/**
+ * Fetches, compiles and includes an external Angular template/HTML.
+ *
+ * A new child [Scope] is created for the included DOM subtree.
+ *
+ * [NgIncludeDirective] provides only one small part of the power of
+ * [NgComponent].  Consider using directives and components instead as they
+ * provide this feature as well as much more.
+ *
+ * Note: The browser's Same Origin Policy (<http://v.gd/5LE5CA>) and
+ * Cross-Origin Resource Sharing (CORS) policy (<http://v.gd/nXoY8y>) restrict
+ * whether the template is successfully loaded.  For example,
+ * [NgIncludeDirective] won't work for cross-domain requests on all browsers and
+ * for `file://` access on some browsers.
+ */
+@NgDirective(
+    selector: '[ng-include]',
+    map: const {'ng-include': '@url'} )
+class NgIncludeDirective {
+
+  dom.Element element;
+  Scope scope;
+  BlockCache blockCache;
+  Injector injector;
+
+  Block _previousBlock;
+  Scope _previousScope;
+
+  NgIncludeDirective(this.element, this.scope, this.blockCache, this.injector);
+
+  _cleanUp() {
+    if (_previousBlock == null) {
+      return;
+    }
+
+    _previousBlock.remove();
+    _previousScope.$destroy();
+    element.innerHtml = '';
+
+    _previousBlock = null;
+    _previousScope = null;
+  }
+
+  _updateContent(createBlock) {
+    // create a new scope
+    _previousScope = scope.$new();
+    _previousBlock = createBlock(injector.createChild([new Module()..value(Scope, _previousScope)]));
+
+    _previousBlock.elements.forEach((elm) => element.append(elm));
+  }
+
+
+  set url(value) {
+    _cleanUp();
+    if (value != null && value != '') {
+      blockCache.fromUrl(value).then(_updateContent);
+    }
+  }
+}