feat(di): drop support for injecting types with generics in Dart

BREAKING CHANGE:
In Dart we used to support injecting types with generics. As this feature is hard to implement with the upcoming codegen we are dropping it.

Merge cl/115454020 in G3 with this change.
Closes #7262

modules/angular2/src/core/di.ts

@@ -31,7 +31,7 @@ export {
   ResolvedProvider,
   provide
 } from './di/provider';
-export {Key, TypeLiteral} from './di/key';
+export {Key} from './di/key';
 export {
   NoProviderError,
   AbstractProviderError,

modules/angular2/src/core/di/key.ts

@@ -1,10 +1,7 @@
 import {stringify, CONST, Type, isBlank} from 'angular2/src/facade/lang';
 import {BaseException, WrappedException} from 'angular2/src/facade/exceptions';
-import {TypeLiteral} from './type_literal';
 import {resolveForwardRef} from './forward_ref';
 
-export {TypeLiteral} from './type_literal';
-
 /**
  * A unique object used for retrieving items from the {@link Injector}.
  *
@@ -53,13 +50,6 @@ export class KeyRegistry {
   get(token: Object): Key {
     if (token instanceof Key) return token;
 
-    // TODO: workaround for https://github.com/Microsoft/TypeScript/issues/3123
-    var theToken = token;
-    if (token instanceof TypeLiteral) {
-      theToken = token.type;
-    }
-    token = theToken;
-
     if (this._allKeys.has(token)) {
       return this._allKeys.get(token);
     }

modules/angular2/src/core/di/type_literal.dart

@@ -1,26 +0,0 @@
-library angular2.di.type_literal;
-
-/**
- * Use type literals as DI keys corresponding to generic types.
- *
- * Example:
- *
- * ```
- * Injector.resolveAndCreate([
- *   bind(new TypeLiteral<List<int>>()).toValue([1, 2, 3])
- * ]);
- *
- * class Foo {
- *   // Delend on `List<int>` normally.
- *   Foo(List<int> list) { ... }
- * }
- * ```
- *
- * This capability might be added to the language one day. See:
- *
- * https://code.google.com/p/dart/issues/detail?id=11923
- */
-class TypeLiteral<T> {
-  const TypeLiteral();
-  Type get type => T;
-}

modules/angular2/src/core/di/type_literal.ts

@@ -1,7 +0,0 @@
-/**
- * Type literals is a Dart-only feature. This is here only so we can x-compile
- * to multiple languages.
- */
-export class TypeLiteral {
-  get type(): any { throw new Error("Type literals are only supported in Dart"); }
-}