Avoid use of empty string as a property name.

sdk/lib/_internal/compiler/implementation/js_emitter/reflection_data_parser.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.
 
 part of dart2js.js_emitter;
 
 // TODO(ahe): Share these with js_helper.dart.
 const FUNCTION_INDEX = 0;
 const NAME_INDEX = 1;
 const CALL_NAME_INDEX = 2;
@@ skipping 206 matching lines @@
 // library is the root library (see dart:mirrors IsolateMirror.rootLibrary).
 //
 // The entries of [data] are built in [assembleProgram] above.
 '''
     var name = data[0];
     var uri = data[1];
     var metadata = data[2];
     var globalObject = data[3];
     var descriptor = data[4];
     var isRoot = !!data[5];
-    var fields = descriptor && descriptor[""];
+    var fields = descriptor && descriptor["${namer.classDescriptorProperty}"];
     var classes = [];
     var functions = [];
 ''';
 
   String processStatics = '''
     function processStatics(descriptor) {
       for (var property in descriptor) {
         if (!hasOwnProperty.call(descriptor, property)) continue;
-        if (property === "") continue;
+        if (property === "${namer.classDescriptorProperty}") continue;
         var element = descriptor[property];
         var firstChar = property.substring(0, 1);
         var previousProperty;
         if (firstChar === "+") {
           mangledGlobalNames[previousProperty] = property.substring(1);
           var flag = descriptor[property];
           if (flag > 0) ''' // Break long line.
          '''descriptor[previousProperty].$reflectableField = flag;
           if (element && element.length) ''' // Break long line.
          '''init.typeInformation[previousProperty] = element;
@@ skipping 99 matching lines @@
 (function() {
   var result = $array[$index];
   if ($check) {
     throw new Error(
         name + ": expected value of type \'$type\' at index " + ($index) +
         " but got " + (typeof result));
   }
   return result;
 })()''';
 }