address feedback

Author: mmalerba

src/material/select/select.ts

@@ -34,8 +34,6 @@ import {
 import {ViewportRuler} from '@angular/cdk/scrolling';
 import {
   AfterContentInit,
-  afterNextRender,
-  AfterRenderPhase,
   Attribute,
   booleanAttribute,
   ChangeDetectionStrategy,
@@ -50,7 +48,6 @@ import {
   Inject,
   inject,
   InjectionToken,
-  Injector,
   Input,
   NgZone,
   numberAttribute,
@@ -545,6 +542,8 @@ export class MatSelect
       ? this._defaultOptions.panelWidth
       : 'auto';
 
+  private _initialized = new Subject();
+
   /** Combined stream of all of the child options' change events. */
   readonly optionSelectionChanges: Observable<MatOptionSelectionChange> = defer(() => {
     const options = this.options;
@@ -556,19 +555,8 @@ export class MatSelect
       );
     }
 
-    return new Observable(subscriber => {
-      afterNextRender(
-        () => {
-          subscriber.next();
-          subscriber.complete();
-        },
-        {
-          injector: this._injector,
-          phase: AfterRenderPhase.Read,
-        },
-      );
-    }).pipe(switchMap(() => this.optionSelectionChanges));
-  }) as Observable<MatOptionSelectionChange>;
+    return this._initialized.pipe(switchMap(() => this.optionSelectionChanges));
+  });
 
   /** Event emitted when the select panel has been toggled. */
   @Output() readonly openedChange: EventEmitter<boolean> = new EventEmitter<boolean>();
@@ -595,8 +583,6 @@ export class MatSelect
    */
   @Output() readonly valueChange: EventEmitter<any> = new EventEmitter<any>();
 
-  private _injector = inject(Injector);
-
   constructor(
     protected _viewportRuler: ViewportRuler,
     protected _changeDetectorRef: ChangeDetectorRef,
@@ -667,6 +653,9 @@ export class MatSelect
   }
 
   ngAfterContentInit() {
+    this._initialized.next();
+    this._initialized.complete();
+
     this._initKeyManager();
 
     this._selectionModel.changed.pipe(takeUntil(this._destroy)).subscribe(event => {