Fix #28120, strong mode allows field overrides

pkg/dev_compiler/lib/src/compiler/class_property_model.dart

Index: pkg/dev_compiler/lib/src/compiler/class_property_model.dart
diff --git a/pkg/dev_compiler/lib/src/compiler/class_property_model.dart b/pkg/dev_compiler/lib/src/compiler/class_property_model.dart
deleted file mode 100644
index 8319c828ffb49350736ae532ed78e5db0e0f86db..0000000000000000000000000000000000000000
--- a/pkg/dev_compiler/lib/src/compiler/class_property_model.dart
+++ /dev/null
@@ -1,95 +0,0 @@
-// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-import 'dart:collection' show HashSet;
-
-import 'package:analyzer/dart/ast/ast.dart' show Identifier;
-import 'package:analyzer/dart/element/element.dart';
-import 'package:analyzer/src/dart/element/element.dart' show FieldElementImpl;
-
-import '../js_ast/js_ast.dart' as JS;
-import 'element_helpers.dart';
-import 'js_names.dart' as JS;
-
-/// Tracks how fields, getters and setters are represented when emitting JS.
-///
-/// Dart classes have implicit features that must be made explicit:
-///
-/// - virtual fields induce a getter and setter pair.
-/// - getters and setters are independent.
-/// - getters and setters can be overridden.
-///
-class ClassPropertyModel {
-  /// Fields that are virtual, that is, they must be generated as a property
-  /// pair in JavaScript.
-  ///
-  /// The value property stores the symbol used for the field's storage slot.
-  final virtualFields = <FieldElement, JS.TemporaryId>{};
-
-  /// Static fields that are overridden, this does not matter for Dart but in
-  /// JS we need to take care initializing these because JS classes inherit
-  /// statics.
-  final staticFieldOverrides = new HashSet<FieldElement>();
-
-  /// The set of inherited getters, used because JS getters/setters are paired,
-  /// so if we're generating a setter we may need to emit a getter that calls
-  /// super.
-  final inheritedGetters = new HashSet<String>();
-
-  /// The set of inherited setters, used because JS getters/setters are paired,
-  /// so if we're generating a getter we may need to emit a setter that calls
-  /// super.
-  final inheritedSetters = new HashSet<String>();
-
-  ClassPropertyModel.build(
-      ClassElement classElem, Iterable<ExecutableElement> extensionMembers) {
-    // Visit superclasses to collect information about their fields/accessors.
-    // This is expensive so we try to collect everything in one pass.
-    for (var base in getSuperclasses(classElem)) {
-      for (var accessor in base.accessors) {
-        // For getter/setter pairs only process them once.
-        if (accessor.correspondingGetter != null) continue;
-
-        var field = accessor.variable;
-        var name = field.name;
-        // Ignore private names from other libraries.
-        if (Identifier.isPrivateName(name) &&
-            accessor.library != classElem.library) {
-          continue;
-        }
-
-        if (field.getter?.isAbstract == false) inheritedGetters.add(name);
-        if (field.setter?.isAbstract == false) inheritedSetters.add(name);
-      }
-    }
-
-    var extensionNames =
-        new HashSet<String>.from(extensionMembers.map((e) => e.name));
-
-    // Visit accessors in the current class, and see if they need to be
-    // generated differently based on the inherited fields/accessors.
-    for (var accessor in classElem.accessors) {
-      // For getter/setter pairs only process them once.
-      if (accessor.correspondingGetter != null) continue;
-      // Also ignore abstract fields.
-      if (accessor.isAbstract) continue;
-
-      var field = accessor.variable;
-      var name = field.name;
-      // Is it a field?
-      if (!field.isSynthetic && field is FieldElementImpl) {
-        if (inheritedGetters.contains(name) ||
-            inheritedSetters.contains(name) ||
-            extensionNames.contains(name) ||
-            field.isVirtual) {
-          if (field.isStatic) {
-            staticFieldOverrides.add(field);
-          } else {
-            virtualFields[field] = new JS.TemporaryId(name);
-          }
-        }
-      }
-    }
-  }
-}