fix(cdk/overlay): run positionChange event inside the zone

Fixes that the `positionChange` event of the `CdkConnectedOverlay` directive was running outside the zone.

Fixes #28568.

src/cdk/overlay/overlay-directives.spec.ts

@@ -1,4 +1,4 @@
-import {Component, ElementRef, ViewChild} from '@angular/core';
+import {Component, ElementRef, NgZone, ViewChild} from '@angular/core';
 import {By} from '@angular/platform-browser';
 import {
   ComponentFixture,
@@ -618,6 +618,18 @@ describe('Overlay directives', () => {
         .toBe(true);
     });
 
+    it('should emit the position change handler inside the zone', () => {
+      let callsInZone: boolean[] = [];
+
+      fixture.componentInstance.positionChangeHandler.and.callFake(() => {
+        callsInZone.push(NgZone.isInAngularZone());
+      });
+      fixture.componentInstance.isOpen = true;
+      fixture.detectChanges();
+
+      expect(callsInZone).toEqual([true]);
+    });
+
     it('should emit when attached', () => {
       expect(fixture.componentInstance.attachHandler).not.toHaveBeenCalled();
       fixture.componentInstance.isOpen = true;

src/cdk/overlay/overlay-directives.ts

@@ -16,6 +16,7 @@ import {
   Inject,
   InjectionToken,
   Input,
+  NgZone,
   OnChanges,
   OnDestroy,
   Optional,
@@ -116,6 +117,7 @@ export class CdkConnectedOverlay implements OnDestroy, OnChanges {
   private _position: FlexibleConnectedPositionStrategy;
   private _scrollStrategyFactory: () => ScrollStrategy;
   private _disposeOnNavigation = false;
+  private _ngZone = inject(NgZone);
 
   /** Origin for the connected overlay. */
   @Input('cdkConnectedOverlayOrigin')
@@ -421,7 +423,7 @@ export class CdkConnectedOverlay implements OnDestroy, OnChanges {
       this._positionSubscription = this._position.positionChanges
         .pipe(takeWhile(() => this.positionChange.observers.length > 0))
         .subscribe(position => {
-          this.positionChange.emit(position);
+          this._ngZone.run(() => this.positionChange.emit(position));
 
           if (this.positionChange.observers.length === 0) {
             this._positionSubscription.unsubscribe();