[web] Do not dispose all platform view factories when disposing a view.

Author: ditman

lib/web_ui/lib/src/engine/canvaskit/embedded_views.dart

@@ -659,7 +659,7 @@ class HtmlViewEmbedder {
 
   /// Disposes the state of this view embedder.
   void dispose() {
-    final Set<int> allViews = PlatformViewManager.instance.debugClear();
+    final Set<int> allViews = PlatformViewManager.instance.getKnownPlatformViewIds();
     disposeViews(allViews);
     _context = EmbedderFrameContext();
     _currentCompositionParams.clear();

lib/web_ui/lib/src/engine/platform_views/content_manager.dart

@@ -212,9 +212,10 @@ class PlatformViewManager {
   /// component.
   bool isVisible(int viewId) => !isInvisible(viewId);
 
-  /// Clears the state. Used in tests.
-  ///
   /// Returns the set of know view ids, so they can be cleaned up.
+  Set<int> getKnownPlatformViewIds() => _contents.keys.toSet();
+
+  /// Clears the state. Used in tests.
   Set<int> debugClear() {
     final Set<int> result = _contents.keys.toSet();
     result.forEach(clearPlatformView);

lib/web_ui/test/canvaskit/multi_view_test.dart

@@ -6,6 +6,7 @@ import 'package:test/bootstrap/browser.dart';
 import 'package:test/test.dart';
 import 'package:ui/src/engine.dart';
 import 'package:ui/ui.dart' as ui;
+import 'package:ui/ui_web/src/ui_web.dart' as ui_web;
 
 import '../common/matchers.dart';
 import 'common.dart';
@@ -68,5 +69,28 @@ void testMain() {
         isNull,
       );
     });
+
+    // Issue https://github.com/flutter/flutter/issues/142094
+    test('does not reset platform view factories when disposing a view', () async {
+      expect(PlatformViewManager.instance.knowsViewType('self-test'), isFalse);
+
+      final EngineFlutterView view = EngineFlutterView(
+          EnginePlatformDispatcher.instance, createDomElement('multi-view'));
+      EnginePlatformDispatcher.instance.viewManager.registerView(view);
+      expect(
+        CanvasKitRenderer.instance.debugGetRasterizerForView(view),
+        isNotNull,
+      );
+
+      EnginePlatformDispatcher.instance.viewManager
+          .disposeAndUnregisterView(view.viewId);
+      expect(
+        CanvasKitRenderer.instance.debugGetRasterizerForView(view),
+        isNull,
+      );
+
+      expect(PlatformViewManager.instance.knowsViewType(ui_web.PlatformViewRegistry.defaultVisibleViewType), isTrue);
+      expect(PlatformViewManager.instance.knowsViewType(ui_web.PlatformViewRegistry.defaultInvisibleViewType), isTrue);
+    });
   });
 }