feat: move observe-content to cdk (#5438)

* Moves the observe content directive to the CDK package.

src/cdk/observe-content/index.ts

@@ -0,0 +1,9 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+export * from './observe-content';

src/cdk/public_api.ts

@@ -13,4 +13,5 @@ export * from './table/index';
 export * from './platform/index';
 export * from './portal/index';
 export * from './rxjs/index';
+export * from './observe-content/index';
 export * from './keyboard/keycodes';

src/lib/checkbox/index.ts

@@ -8,7 +8,8 @@
 
 import {NgModule} from '@angular/core';
 import {CommonModule} from '@angular/common';
-import {MdRippleModule, MdCommonModule, FocusOriginMonitor, ObserveContentModule} from '../core';
+import {ObserveContentModule} from '@angular/cdk';
+import {MdRippleModule, MdCommonModule, FocusOriginMonitor} from '../core';
 import {MdCheckbox} from './checkbox';
 
 

src/lib/core/core.ts

@@ -7,9 +7,9 @@
  */
 
 import {NgModule} from '@angular/core';
+import {ObserveContentModule} from '@angular/cdk';
 import {MdLineModule} from './line/line';
 import {BidiModule} from './bidi/index';
-import {ObserveContentModule} from './observe-content/observe-content';
 import {MdOptionModule} from './option/index';
 import {PortalModule} from './portal/portal-directives';
 import {OverlayModule} from './overlay/index';
@@ -18,14 +18,16 @@ import {MdSelectionModule} from './selection/index';
 import {MdRippleModule} from './ripple/index';
 
 // Re-exports of the CDK to avoid breaking changes.
-export {coerceBooleanProperty, coerceNumberProperty} from '@angular/cdk';
+export {
+  coerceBooleanProperty,
+  coerceNumberProperty,
+  ObserveContentModule,
+  ObserveContent
+} from '@angular/cdk';
 
 // RTL
 export {Dir, Direction, Directionality, BidiModule} from './bidi/index';
 
-// Mutation Observer
-export {ObserveContentModule, ObserveContent} from './observe-content/observe-content';
-
 export * from './option/index';
 
 // Portals

src/lib/tabs/index.ts

@@ -8,9 +8,9 @@
 
 import {NgModule} from '@angular/core';
 import {CommonModule} from '@angular/common';
+import {ObserveContentModule} from '@angular/cdk';
 import {PortalModule} from '../core';
 import {MdRippleModule} from '../core/ripple/index';
-import {ObserveContentModule} from '../core/observe-content/observe-content';
 import {MdTab} from './tab';
 import {MdTabGroup} from './tab-group';
 import {MdTabLabel} from './tab-label';