fix #27258, don't allow dynamic set of a final field

pkg/dev_compiler/tool/input_sdk/private/js_mirrors.dart

 // Copyright (c) 2015, 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 dart._js_mirrors;
 
 import 'dart:mirrors';
 import 'dart:_foreign_helper' show JS;
 import 'dart:_internal' as _internal;
 
@@ skipping 342 matching lines @@
       if (constructors.isEmpty) {
         // Add a default
         var name = 'new';
         var ft = _defaultConstructorType(_unwrap(_cls));
         var symbol = new Symbol(name);
         _declarations[symbol] =
             new JsMethodMirror._constructor(this, symbol, ft);
       }
       var fields = _getFields(unwrapped);
       fields.forEach((symbol, t) {
-        var metadata = [];
-        if (t is List) {
-          metadata = t.skip(1).toList();
-          t = t[0];
-        }
-        _declarations[symbol] =
-            new JsVariableMirror._(symbol, _wrap(t), metadata);
+        _declarations[symbol] = new JsVariableMirror._fromField(symbol, t);
       });
       var methods = _getMethods(unwrapped);
       methods.forEach((symbol, ft) {
         var name = getName(symbol);
         _declarations[symbol] =
             new JsMethodMirror._instanceMethod(this, symbol, ft);
       });
       var getters = _getGetters(unwrapped);
       getters.forEach((symbol, ft) {
         var name = getName(symbol);
         _declarations[symbol] =
             new JsMethodMirror._instanceMethod(this, symbol, ft);
       });
       var setters = _getSetters(unwrapped);
       setters.forEach((symbol, ft) {
         var name = getName(symbol) + '=';
         // Create a separate symbol for the setter.
         symbol = new _internal.PrivateSymbol(name, _getESSymbol(symbol));
         _declarations[symbol] =
             new JsMethodMirror._instanceMethod(this, symbol, ft);
       });
       var staticFields = _getStaticFields(unwrapped);
       staticFields.forEach((symbol, t) {
-        var name = getName(symbol);
-        var metadata = [];
-        if (t is List) {
-          metadata = t.skip(1).toList();
-          t = t[0];
-        }
-        _declarations[symbol] =
-            new JsVariableMirror._(symbol, _wrap(t), metadata);
+        _declarations[symbol] = new JsVariableMirror._fromField(symbol, t);
       });
       var statics = _getStatics(unwrapped);
       statics.forEach((symbol, ft) {
         var name = getName(symbol);
         _declarations[symbol] =
             new JsMethodMirror._staticMethod(this, symbol, ft);
       });
       var staticGetters = _getStaticGetters(unwrapped);
       staticGetters.forEach((symbol, ft) {
         var name = getName(symbol);
@@ skipping 119 matching lines @@
   }
 
   String toString() => "ClassMirror on '$_cls'";
 }
 
 class JsVariableMirror extends JsMirror implements VariableMirror {
   final Symbol _symbol;
   final String _name;
   final TypeMirror type;
   final List<InstanceMirror> metadata;
+  final bool isFinal;
 
   // TODO(vsm): Refactor this out.
   Symbol get simpleName => _symbol;
 
   // TODO(vsm): Fix this
   final bool isStatic = false;
-  final bool isFinal = false;
 
-  JsVariableMirror._(Symbol symbol, Type t, List annotations)
+  JsVariableMirror._(Symbol symbol, Type t, List annotations,
+      {this.isFinal: false})
       : _symbol = symbol,
         _name = getName(symbol),
         type = reflectType(t),
-        metadata = new List<InstanceMirror>.unmodifiable(
-            annotations.map((a) => reflect(a)));
+        metadata =
+            new List<InstanceMirror>.unmodifiable(annotations.map(reflect));
+
+  JsVariableMirror._fromField(Symbol symbol, fieldInfo)
+      : this._(symbol, _wrap(JS('', '#.type', fieldInfo)),
+            JS('', '#.metadata', fieldInfo),
+            isFinal: JS('bool', '#.isFinal', fieldInfo));
 
   String toString() => "VariableMirror on '$_name'";
 }
 
 class JsParameterMirror extends JsVariableMirror implements ParameterMirror {
   JsParameterMirror._(Symbol member, Type t, List annotations)
       : super._(member, t, annotations);
 
   String toString() => "ParameterMirror on '$_name'";
 }
@@ skipping 90 matching lines @@
       var param =
           new JsParameterMirror._(new Symbol(''), _wrap(type), metadata);
       params[i + args.length] = param;
     }
 
     _params = new List.unmodifiable(params);
   }
 
   String toString() => "MethodMirror on '$_name'";
 }