fix: public api surface fixes + stability markers

- ts-api-guardian will now error if a new public symbol is added with a stability marker (`@stable`, `@experimental`, `@deprecated`)
- DomEventsPlugin and KeyEventsPlugin were removed from public api surface - these classes is an implementation detail
- deprecated BROWSER_PROVIDERS was removed completely
- `@angular/compiler` was removed from the ts-api-guardian check since this package shouldn't contain anything that users need to directly import
- the rest of the api surface was conservatively marked as stable or experimental

BREAKING CHANGES: DomEventsPlugin and KeyEventsPlugin previously exported from core are no longer public - these classes are implementation detail.

Previously deprecated BROWSER_PROVIDERS was completely removed from platform-browser.

Closes #9236
Closes #9235
Ref #9234

modules/@angular/core/testing/async.ts

@@ -24,6 +24,8 @@ var _global = <any>(typeof window === 'undefined' ? global : window);
  *   })
  * });
  * ```
+ *
+ * @stable
  */
 export function async(fn: Function): (done: any) => any {
   // If we're running using the Jasmine test framework, adapt to call the 'done'

modules/@angular/core/testing/component_fixture.ts

@@ -16,6 +16,8 @@ import {tick} from './fake_async';
 
 /**
  * Fixture for debugging and testing a component.
+ *
+ * @stable
  */
 export class ComponentFixture<T> {
   /**

modules/@angular/core/testing/fake_async.ts

@@ -25,6 +25,8 @@ let _FakeAsyncTestZoneSpecType = (Zone as any /** TODO #9100 */)['FakeAsyncTestZ
  *
  * @param fn
  * @returns {Function} The function wrapped to be executed in the fakeAsync zone
+ *
+ * @experimental
  */
 export function fakeAsync(fn: Function): (...args: any[]) => any {
   if (Zone.current.get('FakeAsyncTestZoneSpec') != null) {
@@ -73,6 +75,7 @@ function _getFakeAsyncZoneSpec(): any {
  *
  * {@example testing/ts/fake_async.ts region='basic'}
  *
+ * @experimental
  */
 export function tick(millis: number = 0): void {
   _getFakeAsyncZoneSpec().tick(millis);
@@ -80,6 +83,8 @@ export function tick(millis: number = 0): void {
 
 /**
  * Discard all remaining periodic tasks.
+ *
+ * @experimental
  */
 export function discardPeriodicTasks(): void {
   let zoneSpec = _getFakeAsyncZoneSpec();
@@ -89,6 +94,8 @@ export function discardPeriodicTasks(): void {
 
 /**
  * Flush any pending microtasks.
+ *
+ * @experimental
  */
 export function flushMicrotasks(): void {
   _getFakeAsyncZoneSpec().flushMicrotasks();

modules/@angular/core/testing/test_component_builder.ts

@@ -16,18 +16,28 @@ import {tick} from './fake_async';
 
 /**
  * An abstract class for inserting the root test component element in a platform independent way.
+ *
+ * @experimental
  */
 export class TestComponentRenderer {
   insertRootElement(rootElementId: string) {}
 }
 
+/**
+ * @experimental
+ */
 export var ComponentFixtureAutoDetect = new OpaqueToken('ComponentFixtureAutoDetect');
+
+/**
+ * @experimental
+ */
 export var ComponentFixtureNoNgZone = new OpaqueToken('ComponentFixtureNoNgZone');
 
 var _nextRootElementId = 0;
 
 /**
  * Builds a ComponentFixture for use in component level tests.
+ * @stable
  */
 @Injectable()
 export class TestComponentBuilder {

modules/@angular/core/testing/test_injector.ts

@@ -13,6 +13,9 @@ import {BaseException} from '../src/facade/exceptions';
 import {FunctionWrapper, isPresent} from '../src/facade/lang';
 import {AsyncTestCompleter} from './async_test_completer';
 
+/**
+ * @experimental
+ */
 export class TestInjector {
   private _instantiated: boolean = false;
 
@@ -64,6 +67,9 @@ export class TestInjector {
 
 var _testInjector: TestInjector = null;
 
+/**
+ * @experimental
+ */
 export function getTestInjector() {
   if (_testInjector == null) {
     _testInjector = new TestInjector();
@@ -81,6 +87,8 @@ export function getTestInjector() {
  *
  * Test Providers for individual platforms are available from
  * 'angular2/platform/testing/<platform_name>'.
+ *
+ * @experimental
  */
 export function setBaseTestProviders(
     platformProviders: Array<Type|Provider|any[]>,
@@ -101,6 +109,8 @@ export function setBaseTestProviders(
 
 /**
  * Reset the providers for the test injector.
+ *
+ * @experimental
  */
 export function resetBaseTestProviders() {
   var testInjector = getTestInjector();
@@ -131,6 +141,7 @@ export function resetBaseTestProviders() {
  * eventually
  *   becomes `it('...', @Inject (object: AClass, async: AsyncTestCompleter) => { ... });`
  *
+ * @stable
  */
 export function inject(tokens: any[], fn: Function): () => any {
   let testInjector = getTestInjector();
@@ -148,6 +159,9 @@ export function inject(tokens: any[], fn: Function): () => any {
   }
 }
 
+/**
+ * @experimental
+ */
 export class InjectSetupWrapper {
   constructor(private _providers: () => any) {}
 
@@ -166,6 +180,9 @@ export class InjectSetupWrapper {
   }
 }
 
+/**
+ * @experimental
+ */
 export function withProviders(providers: () => any) {
   return new InjectSetupWrapper(providers);
 }

modules/@angular/core/testing/testing.ts

@@ -117,6 +117,8 @@ if (_global.beforeEach) {
 /**
  * Allows overriding default providers of the test injector,
  * which are defined in test_injector.js
+ *
+ * @stable
  */
 export function addProviders(providers: Array<any>): void {
   if (!providers) return;