feat(ElementInjector): implement ElementInjector

modules/core/src/annotations/visibility.js

@@ -0,0 +1,22 @@
+import {CONST} from 'facade/lang';
+import {DependencyAnnotation} from 'di/di';
+
+/**
+ * The directive can only be injected from the current element
+ * or from its parent.
+ */
+export class Parent extends DependencyAnnotation {
+  @CONST()
+  constructor() {
+  }
+}
+
+/**
+ * The directive can only be injected from the current element
+ * or from its ancestor.
+ */
+export class Ancestor extends DependencyAnnotation {
+  @CONST()
+  constructor() {
+  }
+}