Fix for 'Obserable.fromEvent is not a function'.

src/lib/core/overlay/scroll/scroll-dispatcher.ts

@@ -2,9 +2,8 @@ import {ElementRef, Injectable, NgZone, Optional, SkipSelf} from '@angular/core'
 import {Platform} from '../../platform/index';
 import {Scrollable} from './scrollable';
 import {Subject} from 'rxjs/Subject';
-import {Observable} from 'rxjs/Observable';
+import {Observable, fromEvent} from 'rxjs';
 import {Subscription} from 'rxjs/Subscription';
-import 'rxjs/add/observable/fromEvent';
 import 'rxjs/add/observable/merge';
 import 'rxjs/add/operator/auditTime';
 
@@ -79,8 +78,8 @@ export class ScrollDispatcher {
     if (!this._globalSubscription) {
       this._globalSubscription = this._ngZone.runOutsideAngular(() => {
         return Observable.merge(
-          Observable.fromEvent(window.document, 'scroll'),
-          Observable.fromEvent(window, 'resize')
+          fromEvent(window.document, 'scroll'),
+          fromEvent(window, 'resize')
         ).subscribe(() => this._notify());
       });
     }