refactor(core): remove …Metadata for all decorators and use the decorator directly.

BREAKING CHANGE:
- all `…Metadata` classes have been removed. Use the corresponding decorator
  as constructor or for `instanceof` checks instead.
- Example:
  * Before: `new ComponentMetadata(…)`
  * After: `new Component(…)`
- Note: `new Component(…)` worked before as well.

modules/@angular/core/src/di/metadata.ts

@@ -14,7 +14,7 @@ import {makeParamDecorator} from '../util/decorators';
  *
  * @stable
  */
-export interface InjectMetadataFactory {
+export interface InjectDecorator {
   /**
    * A parameter metadata that specifies a dependency.
    *
@@ -74,7 +74,7 @@ export interface Inject { token: any; }
  * @stable
  * @Annotation
  */
-export const Inject: InjectMetadataFactory = makeParamDecorator([['token', undefined]]);
+export const Inject: InjectDecorator = makeParamDecorator([['token', undefined]]);
 
 
 /**
@@ -82,7 +82,7 @@ export const Inject: InjectMetadataFactory = makeParamDecorator([['token', undef
  *
  * @stable
  */
-export interface OptionalMetadataFactory {
+export interface OptionalDecorator {
   /**
    * A parameter metadata that marks a dependency as optional. {@link Injector} provides `null` if
    * the dependency is not found.
@@ -122,14 +122,14 @@ export interface Optional {}
  * @stable
  * @Annotation
  */
-export const Optional: OptionalMetadataFactory = makeParamDecorator([]);
+export const Optional: OptionalDecorator = makeParamDecorator([]);
 
 /**
  * Type of the Injectable decorator / constructor function.
  *
  * @stable
  */
-export interface InjectableMetadataFactory {
+export interface InjectableDecorator {
   /**
    * A marker metadata that marks a class as available to {@link Injector} for creation.
    *
@@ -179,14 +179,14 @@ export interface Injectable {}
  * @stable
  * @Annotation
  */
-export const Injectable: InjectableMetadataFactory = makeParamDecorator([]);
+export const Injectable: InjectableDecorator = makeParamDecorator([]);
 
 /**
  * Type of the Self decorator / constructor function.
  *
  * @stable
  */
-export interface SelfMetadataFactory {
+export interface SelfDecorator {
   /**
    * Specifies that an {@link Injector} should retrieve a dependency only from itself.
    *
@@ -232,7 +232,7 @@ export interface Self {}
  * @stable
  * @Annotation
  */
-export const Self: SelfMetadataFactory = makeParamDecorator([]);
+export const Self: SelfDecorator = makeParamDecorator([]);
 
 
 /**
@@ -240,7 +240,7 @@ export const Self: SelfMetadataFactory = makeParamDecorator([]);
  *
  * @stable
  */
-export interface SkipSelfMetadataFactory {
+export interface SkipSelfDecorator {
   /**
    * Specifies that the dependency resolution should start from the parent injector.
    *
@@ -284,14 +284,14 @@ export interface SkipSelf {}
  * @stable
  * @Annotation
  */
-export const SkipSelf: SkipSelfMetadataFactory = makeParamDecorator([]);
+export const SkipSelf: SkipSelfDecorator = makeParamDecorator([]);
 
 /**
  * Type of the Host decorator / constructor function.
  *
  * @stable
  */
-export interface HostMetadataFactory {
+export interface HostDecorator {
   /**
    * Specifies that an injector should retrieve a dependency from any injector until reaching the
    * closest host.
@@ -362,14 +362,4 @@ export interface Host {}
  * @stable
  * @Annotation
  */
-export const Host: HostMetadataFactory = makeParamDecorator([]);
-
-// TODO(tbosch): remove this
-export {
-  Host as HostMetadata,
-  Inject as InjectMetadata,
-  Injectable as InjectableMetadata,
-  Optional as OptionalMetadata,
-  Self as SelfMetadata,
-  SkipSelf as SkipSelfMetadata
-};
+export const Host: HostDecorator = makeParamDecorator([]);

modules/@angular/core/src/di/reflective_injector.ts

@@ -11,7 +11,7 @@ import {unimplemented} from '../facade/errors';
 import {Type} from '../type';
 
 import {Injector, THROW_IF_NOT_FOUND} from './injector';
-import {SelfMetadata, SkipSelfMetadata} from './metadata';
+import {Self, SkipSelf} from './metadata';
 import {Provider} from './provider';
 import {AbstractProviderError, CyclicDependencyError, InstantiationError, NoProviderError, OutOfBoundsError} from './reflective_errors';
 import {ReflectiveKey} from './reflective_key';
@@ -807,7 +807,7 @@ export class ReflectiveInjector_ implements ReflectiveInjector {
       return this;
     }
 
-    if (upperBoundVisibility instanceof SelfMetadata) {
+    if (upperBoundVisibility instanceof Self) {
       return this._getByKeySelf(key, notFoundValue);
 
     } else {
@@ -834,7 +834,7 @@ export class ReflectiveInjector_ implements ReflectiveInjector {
   _getByKeyDefault(key: ReflectiveKey, notFoundValue: any, lowerBoundVisibility: Object): any {
     var inj: Injector;
 
-    if (lowerBoundVisibility instanceof SkipSelfMetadata) {
+    if (lowerBoundVisibility instanceof SkipSelf) {
       inj = this._parent;
     } else {
       inj = this;

modules/@angular/core/src/di/reflective_provider.ts

@@ -12,7 +12,7 @@ import {reflector} from '../reflection/reflection';
 import {Type} from '../type';
 
 import {resolveForwardRef} from './forward_ref';
-import {HostMetadata, InjectMetadata, OptionalMetadata, SelfMetadata, SkipSelfMetadata} from './metadata';
+import {Host, Inject, Optional, Self, SkipSelf} from './metadata';
 import {ClassProvider, ExistingProvider, FactoryProvider, Provider, TypeProvider, ValueProvider} from './provider';
 import {InvalidProviderError, MixingMultiProvidersWithRegularProvidersError, NoAnnotationError} from './reflective_errors';
 import {ReflectiveKey} from './reflective_key';
@@ -226,7 +226,7 @@ function _extractToken(
   var optional = false;
 
   if (!isArray(metadata)) {
-    if (metadata instanceof InjectMetadata) {
+    if (metadata instanceof Inject) {
       return _createDependency(metadata.token, optional, null, null, depProps);
     } else {
       return _createDependency(metadata, optional, null, null, depProps);
@@ -242,19 +242,19 @@ function _extractToken(
     if (paramMetadata instanceof Type) {
       token = paramMetadata;
 
-    } else if (paramMetadata instanceof InjectMetadata) {
+    } else if (paramMetadata instanceof Inject) {
       token = paramMetadata.token;
 
-    } else if (paramMetadata instanceof OptionalMetadata) {
+    } else if (paramMetadata instanceof Optional) {
       optional = true;
 
-    } else if (paramMetadata instanceof SelfMetadata) {
+    } else if (paramMetadata instanceof Self) {
       upperBoundVisibility = paramMetadata;
 
-    } else if (paramMetadata instanceof HostMetadata) {
+    } else if (paramMetadata instanceof Host) {
       upperBoundVisibility = paramMetadata;
 
-    } else if (paramMetadata instanceof SkipSelfMetadata) {
+    } else if (paramMetadata instanceof SkipSelf) {
       lowerBoundVisibility = paramMetadata;
     }
   }