Add a flag to always bind scheduleRead/Write to execute in the curren…

…t Zone.

[THIS CL IS A NO-OP: It makes no changes unless you opt-in to a new flag]

To opt-in, add the following to your "main()" function:
  DomService.maintainZoneOnCallbacks = true;

This complies with the contract of `dart:async`, which expects all asynchronous code that doesn't use Futures or Streams to either document that it doesn't comply or always re-enter the current zone on execution. This code is basically equivalent to:

final currentZone = Zone.current;
queue.add(() {
  currentZone.run(fn);
});

The goal is eventually to make this the default, allow users to opt-out, and then remove the flag entirely (no more opt-outs). The scope of changes internally looks quite small based on tests only, but some application behavior could change.

PiperOrigin-RevId: 199502477

lib/utils/browser/dom_service/dom_service.dart

@@ -23,6 +23,18 @@ 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 `true`, it means:
+  /// * [Zone.current] will be restored when the callbacks are executed.
+  /// * AngularDart (or any parent zone) will know about the change.
+  static bool maintainZoneOnCallbacks = false;
+
   static const _TURN_DONE_EVENT_TYPE = 'doms-turn';
 
   /// The maximum time the idle scheduler waits between events.
@@ -241,6 +253,9 @@ class DomService {
   }
 
   void _scheduleInQueue(DomReadWriteFn fn, List<DomReadWriteFn> queue) {
+    if (maintainZoneOnCallbacks) {
+      fn = Zone.current.bindCallback(fn);
+    }
     queue.add(fn);
     _scheduleProcessQueue();
   }