fix(api): remove UNDEFINED

modules/angular2/src/core/compiler/element_injector.ts

@@ -13,7 +13,6 @@ import {
   Injector,
   ProtoInjector,
   Visibility,
-  UNDEFINED,
   Key,
   Dependency,
   bind,
@@ -25,6 +24,7 @@ import {
   resolveForwardRef,
   DependencyProvider
 } from 'angular2/src/core/di';
+import {UNDEFINED} from 'angular2/src/core/di/injector';
 import {
   InjectorInlineStrategy,
   InjectorDynamicStrategy,

modules/angular2/src/core/di.ts

@@ -23,8 +23,7 @@ export {
   ProtoInjector,
   BindingWithVisibility,
   DependencyProvider,
-  Visibility,
-  UNDEFINED
+  Visibility
 } from './di/injector';
 export {
   Binding,

modules/angular2/src/router/router_outlet.ts

@@ -5,7 +5,7 @@ import {BaseException, WrappedException} from 'angular2/src/core/facade/exceptio
 
 import {Directive, Attribute} from 'angular2/src/core/metadata';
 import {DynamicComponentLoader, ComponentRef, ElementRef} from 'angular2/src/core/compiler';
-import {Injector, bind, Dependency, UNDEFINED} from 'angular2/src/core/di';
+import {Injector, bind, Dependency} from 'angular2/src/core/di';
 
 import * as routerMod from './router';
 import {ComponentInstruction, RouteParams} from './instruction';

modules/angular2/test/public_api_spec.ts

@@ -848,8 +848,6 @@ const NG_API = [
   'TypeLiteral',
   'TypeLiteral.type',
 
-  'UNDEFINED',  // TODO: private
-
   'UpperCasePipe',
   'UpperCasePipe.transform',