address comments

Author: mmalerba

src/cdk-experimental/scrolling/virtual-scroll-viewport.spec.ts

@@ -6,7 +6,7 @@ import {animationFrameScheduler, Subject} from 'rxjs';
 import {CdkVirtualScrollViewport, CdkVirtualForOf, ScrollingModule} from './index';
 
 
-fdescribe('CdkVirtualScrollViewport', () => {
+describe('CdkVirtualScrollViewport', () => {
   describe ('with FixedSizeVirtualScrollStrategy', () => {
     let fixture: ComponentFixture<FixedSizeVirtualScroll>;
     let testComponent: FixedSizeVirtualScroll;

src/cdk-experimental/scrolling/virtual-scroll-viewport.ts

@@ -150,9 +150,9 @@ export class CdkVirtualScrollViewport implements OnInit, OnDestroy {
     this._ngZone.runOutsideAngular(() => {
       this._forOf = forOf;
       this._forOf.dataStream.pipe(takeUntil(this._detachedSubject)).subscribe(data => {
-        const len = data.length;
-        if (len !== this._dataLength) {
-          this._dataLength = len;
+        const newLength = data.length;
+        if (newLength !== this._dataLength) {
+          this._dataLength = newLength;
           this._scrollStrategy.onDataLengthChanged();
         }
       });