Attempt to fix CI failure.

Author: kseamon

src/cdk-experimental/column-resize/column-resize.ts

@@ -11,7 +11,7 @@ import {Directionality} from '@angular/cdk/bidi';
 import {fromEvent, merge, ReplaySubject} from 'rxjs';
 import {filter, map, mapTo, pairwise, startWith, take, takeUntil} from 'rxjs/operators';
 
-import {closest, matches} from '@angular/cdk-experimental/popover-edit/polyfill';
+import {_closest, _matches} from '@angular/cdk-experimental/popover-edit';
 
 import {ColumnResizeNotifier, ColumnResizeNotifierSource} from './column-resize-notifier';
 import {HEADER_CELL_SELECTOR, RESIZE_OVERLAY_SELECTOR} from './constants';
@@ -65,12 +65,12 @@ export abstract class ColumnResize implements AfterViewInit, OnDestroy {
 
       fromEvent<MouseEvent>(element, 'mouseover').pipe(
           takeUntil(this.destroyed),
-          map(event => closest(event.target, HEADER_CELL_SELECTOR)),
+          map(event => _closest(event.target, HEADER_CELL_SELECTOR)),
           ).subscribe(this.eventDispatcher.headerCellHovered);
       fromEvent<MouseEvent>(element, 'mouseleave').pipe(
           takeUntil(this.destroyed),
           filter(event => !!event.relatedTarget &&
-              !matches(event.relatedTarget as Element, RESIZE_OVERLAY_SELECTOR)),
+              !_matches(event.relatedTarget as Element, RESIZE_OVERLAY_SELECTOR)),
           mapTo(null),
           ).subscribe(this.eventDispatcher.headerCellHovered);
     });

src/cdk-experimental/column-resize/event-dispatcher.ts

@@ -10,7 +10,7 @@ import {Injectable, NgZone} from '@angular/core';
 import {combineLatest, MonoTypeOperatorFunction, Observable, Subject} from 'rxjs';
 import {distinctUntilChanged, map, share, skip, startWith} from 'rxjs/operators';
 
-import {closest} from '@angular/cdk-experimental/popover-edit/polyfill';
+import {_closest} from '@angular/cdk-experimental/popover-edit';
 
 import {HEADER_ROW_SELECTOR} from './constants';
 
@@ -30,12 +30,12 @@ export class HeaderRowEventDispatcher {
 
   readonly headerRowHoveredOrActiveDistinct = combineLatest(
       this.headerCellHoveredDistinct.pipe(
-          map(cell => closest(cell, HEADER_ROW_SELECTOR)),
+          map(cell => _closest(cell, HEADER_ROW_SELECTOR)),
           startWith(null),
           distinctUntilChanged(),
        ),
       this.overlayHandleActiveForCell.pipe(
-          map(cell => closest(cell, HEADER_ROW_SELECTOR)),
+          map(cell => _closest(cell, HEADER_ROW_SELECTOR)),
           startWith(null),
           distinctUntilChanged(),
       ),

src/cdk-experimental/column-resize/overlay-handle.ts

@@ -22,7 +22,7 @@ import {
   takeUntil,
 } from 'rxjs/operators';
 
-import {closest} from '@angular/cdk-experimental/popover-edit/polyfill';
+import {_closest} from '@angular/cdk-experimental/popover-edit';
 
 import {HEADER_CELL_SELECTOR} from './constants';
 import {ColumnResizeNotifierSource} from './column-resize-notifier';
@@ -66,7 +66,7 @@ export abstract class ResizeOverlayHandle implements AfterViewInit, OnDestroy {
       fromEvent<MouseEvent>(this.elementRef.nativeElement!, 'mouseleave').pipe(
           takeUntilDestroyed,
           map(event => event.relatedTarget &&
-              closest(event.relatedTarget as Element, HEADER_CELL_SELECTOR)),
+              _closest(event.relatedTarget as Element, HEADER_CELL_SELECTOR)),
       ).subscribe(cell => this.eventDispatcher.headerCellHovered.next(cell));
 
       fromEvent<MouseEvent>(this.elementRef.nativeElement!, 'mousedown')

src/cdk-experimental/column-resize/resizable.ts

@@ -22,7 +22,7 @@ import {CdkColumnDef} from '@angular/cdk/table';
 import {merge, ReplaySubject} from 'rxjs';
 import {filter, takeUntil} from 'rxjs/operators';
 
-import {closest} from '@angular/cdk-experimental/popover-edit/polyfill';
+import {_closest} from '@angular/cdk-experimental/popover-edit';
 
 import {HEADER_ROW_SELECTOR} from './constants';
 import {ResizeOverlayHandle} from './overlay-handle';
@@ -132,7 +132,7 @@ export abstract class Resizable<HandleComponent extends ResizeOverlayHandle>
     const takeUntilDestroyed = takeUntil<boolean>(this.destroyed);
 
 
-    this.eventDispatcher.resizeOverlayVisibleForHeaderRow(closest(element, HEADER_ROW_SELECTOR)!)
+    this.eventDispatcher.resizeOverlayVisibleForHeaderRow(_closest(element, HEADER_ROW_SELECTOR)!)
         .pipe(takeUntilDestroyed).subscribe(hoveringRow => {
       if (hoveringRow) {
         if (!this.overlayRef) {

src/cdk-experimental/popover-edit/public-api.ts

@@ -15,5 +15,6 @@ export * from './popover-edit-module';
 export * from './popover-edit-position-strategy-factory';
 export * from './table-directives';
 
+// Private to Angular Components
 export {CELL_SELECTOR as _CELL_SELECTOR} from './constants';
-export {closest as _closest} from './polyfill';
+export {closest as _closest, matches as _matches} from './polyfill';