Don't resynthesize field types during class members resynthesis.

pkg/analyzer/lib/src/dart/element/element.dart

 // Copyright (c) 2014, 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.
 
 library analyzer.src.dart.element.element;
 
 import 'dart:collection';
 import 'dart:math' show min;
 
 import 'package:analyzer/dart/ast/ast.dart';
@@ skipping 1190 matching lines @@
     }
     // Build explicit property accessors and implicit fields.
     var explicitAccessors = <PropertyAccessorElement>[];
     var implicitFields = <String, FieldElementImpl>{};
     for (UnlinkedExecutable e in _unlinkedClass.executables) {
       if (e.kind == UnlinkedExecutableKind.getter ||
           e.kind == UnlinkedExecutableKind.setter) {
         PropertyAccessorElementImpl accessor =
             new PropertyAccessorElementImpl.forSerialized(e, this);
         explicitAccessors.add(accessor);
-        // Prepare the field type.
-        DartType fieldType;
-        if (e.kind == UnlinkedExecutableKind.getter) {
-          fieldType = accessor.returnType;
-        } else {
-          List<ParameterElement> parameters = accessor.parameters;
-          fieldType = parameters.isNotEmpty
-              ? parameters[0].type
-              : DynamicTypeImpl.instance;
-        }
         // Create or update the implicit field.
         String fieldName = accessor.displayName;
         FieldElementImpl field = implicitFields[fieldName];
         if (field == null) {
           field = new FieldElementImpl(fieldName, -1);
           implicitFields[fieldName] = field;
           field.enclosingElement = this;
           field.isSynthetic = true;
           field.isFinal = e.kind == UnlinkedExecutableKind.getter;
-          field.type = fieldType;
           field.isStatic = e.isStatic;
         } else {
           field.isFinal = false;
         }
         accessor.variable = field;
         if (e.kind == UnlinkedExecutableKind.getter) {
           field.getter = accessor;
         } else {
           field.setter = accessor;
         }
@@ skipping 5659 matching lines @@
   DartType get type {
     if (_unlinkedVariable != null && _declaredType == null && _type == null) {
       _type = enclosingUnit.resynthesizerContext.resolveLinkedType(
           _unlinkedVariable.inferredTypeSlot, typeParameterContext);
       _declaredType = enclosingUnit.resynthesizerContext
           .resolveTypeRef(_unlinkedVariable.type, typeParameterContext);
     }
     return super.type;
   }
 
+  @override
   void set type(DartType type) {
     _assertNotResynthesized(_unlinkedVariable);
     _type = type;
   }
 
   /**
    * Subclasses need this getter, see [ConstVariableElement._unlinkedConst].
    */
   UnlinkedExpr get _unlinkedConst => _unlinkedVariable?.initializer?.bodyExpr;
 }
@@ skipping 960 matching lines @@
       _propagatedType = enclosingUnit.resynthesizerContext.resolveLinkedType(
           _unlinkedVariable.propagatedTypeSlot, typeParameterContext);
     }
     return _propagatedType;
   }
 
   void set propagatedType(DartType propagatedType) {
     _assertNotResynthesized(_unlinkedVariable);
     _propagatedType = propagatedType;
   }
+
+  @override
+  DartType get type {
+    if (isSynthetic && _type == null) {
+      if (getter != null) {
+        _type = getter.returnType;
+      } else if (setter != null) {
+        List<ParameterElement> parameters = setter.parameters;
+        _type = parameters.isNotEmpty
+            ? parameters[0].type
+            : DynamicTypeImpl.instance;
+      } else {
+        _type = DynamicTypeImpl.instance;
+      }
+    }
+    return super.type;
+  }
 }
 
 /**
  * The context in which elements are resynthesized.
  */
 abstract class ResynthesizerContext {
   bool get isStrongMode;
 
   /**
    * Build [ElementAnnotationImpl] for the given [UnlinkedExpr].
@@ skipping 725 matching lines @@
 
   @override
   void visitElement(Element element) {
     int offset = element.nameOffset;
     if (offset != -1) {
       map[offset] = element;
     }
     super.visitElement(element);
   }
 }