Bring back the re-entry flag for DomService since performance problems have been encountered with the value flipped. We won't be flipping any other values, but will give the flag back to unblock them.

PiperOrigin-RevId: 208876710

Author: TedSander

lib/utils/browser/dom_service/dom_service.dart

@@ -23,6 +23,19 @@ typedef Future<num> RequestAnimationFrame();
 /// Utility class to synchronize DOM operations across components, e.g. to check
 /// changes in the layout after a UI update or application event.
 class DomService {
+  /// Whether to execute functions scheduled within [Zone.current].
+  ///
+  /// This is the expected behavior and contract of Dart applications, but is
+  /// not applied automatically to every callback (only to Futures and Streams).
+  /// Eventually, this flag will be flipped to `true`, and deleted (all code
+  /// must use this behavior).
+  ///
+  /// By flipping this to `false`, it means:
+  /// * [Zone.current] will be not be restored when the callbacks are executed.
+  /// * AngularDart (or any parent zone) will not know about the change.
+  @Deprecated('For legacy reasons. DO NOT USE unless you talk to AngularDart.')
+  static bool maintainZoneOnCallbacks = true;
+
   static const _TURN_DONE_EVENT_TYPE = 'doms-turn';
 
   /// The maximum time the idle scheduler waits between events.
@@ -241,7 +254,9 @@ class DomService {
   }
 
   void _scheduleInQueue(DomReadWriteFn fn, List<DomReadWriteFn> queue) {
-    fn = Zone.current.bindCallback(fn);
+    if (maintainZoneOnCallbacks) {
+      fn = Zone.current.bindCallback(fn);
+    }
     queue.add(fn);
     _scheduleProcessQueue();
   }