It is not an error anymore to leave an instance final field uninitialized.

runtime/vm/parser.h

 // Copyright (c) 2012, 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.
 
 #ifndef VM_PARSER_H_
 #define VM_PARSER_H_
 
 #include "include/dart_api.h"
 
 #include "lib/invocation_mirror.h"
@@ skipping 377 matching lines @@
                                   intptr_t metadata_pos);
   void ParseFormalParameter(bool allow_explicit_default_value,
                             bool evaluate_metadata,
                             ParamList* params);
   void ParseFormalParameters(bool allow_explicit_default_values,
                              bool evaluate_metadata,
                              ParamList* params);
   void ParseFormalParameterList(bool allow_explicit_default_values,
                                 bool evaluate_metadata,
                                 ParamList* params);
-  void CheckConstFieldsInitialized(const Class& cls);
+  void CheckFieldsInitialized(const Class& cls);
   static void AddImplicitConstructor(const Class& cls);
   void CheckConstructors(ClassDesc* members);
   AstNode* ParseExternalInitializedField(const Field& field);
   void ParseInitializedInstanceFields(
       const Class& cls,
       LocalVariable* receiver,
       GrowableArray<Field*>* initialized_fields);
   void CheckDuplicateFieldInit(intptr_t init_pos,
                                GrowableArray<Field*>* initialized_fields,
                                Field* field);
@@ skipping 308 matching lines @@
   intptr_t last_used_try_index_;
 
   bool unregister_pending_function_;
 
   DISALLOW_COPY_AND_ASSIGN(Parser);
 };
 
 }  // namespace dart
 
 #endif  // VM_PARSER_H_