Adding Angular and dependent packages for testing

third_party/pkg/angular/test/filter/json_spec.dart

Index: third_party/pkg/angular/test/filter/json_spec.dart
diff --git a/third_party/pkg/angular/test/filter/json_spec.dart b/third_party/pkg/angular/test/filter/json_spec.dart
new file mode 100644
index 0000000000000000000000000000000000000000..20b3fd8fd5895a303f3371c2276e4500778d5d54
--- /dev/null
+++ b/third_party/pkg/angular/test/filter/json_spec.dart
@@ -0,0 +1,10 @@
+library json_spec;
+
+import '../_specs.dart';
+
+main() => describe('json', () {
+  it('should convert primitives, array, map to json', inject((Scope scope) {
+    scope.foo = [{"string":'foo', "number": 123, "bool": false}];
+    expect(scope.$eval('foo | json')).toEqual('[{"string":"foo","number":123,"bool":false}]');
+  }));
+});