Adding Angular and dependent packages for testing

third_party/pkg/angular/lib/tools/template_cache_annotation.dart

+library angular.template_cache_annotation;
+
+/**
+ * Annotation which will control the caching behavior of objects in the
+ * template_cache.
+ *
+ * Primary use cases are:
+ *   - Adding URLs to the cache which cannot be automatically gathered from
+ *   NgComponent annotations.
+ *   - Adding annotation to an NgComponent to remove it from the template cache.
+ */
+class NgTemplateCache {
+  // List of strings to add to the template cache.
+  final List<String> preCacheUrls;
+  // Whether to cache these resources in the template cache. Primary use is to
+  // override the default caching behavior for NgComponent annotation.
+  final bool cache;
+
+  const NgTemplateCache(
+      {this.preCacheUrls : const <String> [], this.cache : true});
+}