Fixes needed in webui for sdk 7.1.0

lib/src/observable_transform.dart

 // Copyright (c) 2013, 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.
 
 /**
  * Code transform for @observable. The core transformation is relatively
  * straightforward, and essentially like an editor refactoring. You can find the
  * core implementation in [transformClass], which is ultimately called by
  * [transformObservables], the entry point to this library.
  */
@@ skipping 107 matching lines @@
 void transformTopLevelField(TopLevelVariableDeclaration field,
     TextEditTransaction code, Set<String> changedFields) {
 
   transformFields(field.variables, code, field.offset, field.end,
       isTopLevel: true, changedFields: changedFields);
 }
 
 void transformClassFields(FieldDeclaration member, TextEditTransaction code,
     Set<String> instanceFields, Set<String> staticFields) {
 
-  bool isStatic = hasKeyword(member.keyword, Keyword.STATIC);
   transformFields(member.fields, code, member.offset, member.end,
-      isStatic: isStatic,
-      changedFields: isStatic ? staticFields : instanceFields);
+      isStatic: member.isStatic,
+      changedFields: member.isStatic ? staticFields : instanceFields);
 }
 
 
 void fixConstructor(ConstructorDeclaration ctor, TextEditTransaction code,
     Set<String> changedFields) {
 
   // Fix normal initializers
   for (var initializer in ctor.initializers) {
     if (initializer is ConstructorFieldInitializer) {
       var field = initializer.fieldName;
@@ skipping 100 matching lines @@
         __\$$name, value);
   }
   __\$$name = value;
 }'''.replaceAll('\n', '\n$indent'));
 
     if (changedFields != null) changedFields.add(name);
   }
 
   code.edit(begin, end, '$replace');
 }