improve unicode support

recipe_engine/third_party/expect_tests/serialize.py

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import difflib
 import json
 import os
 import pprint
 
 from collections import OrderedDict
@@ skipping 10 matching lines @@
 SUPPORTED_SERIALIZERS = {'json', 'yaml'}
 SERIALIZERS = {}
 
 
 # JSON support
 def re_encode(obj):
   if isinstance(obj, dict):
     return {re_encode(k): re_encode(v) for k, v in obj.iteritems()}
   elif isinstance(obj, list):
     return [re_encode(i) for i in obj]
-  elif isinstance(obj, unicode):
-    return obj.encode('utf-8')
+  elif isinstance(obj, str):
+    return obj.decode('utf-8')
   else:
     return obj
 
 
 SERIALIZERS['json'] = (
     lambda s: re_encode(json.load(s)),
     lambda data, stream: json.dump(
         data, stream, sort_keys=True, indent=2, separators=(',', ': ')))
 
 
@@ skipping 75 matching lines @@
     return new
   if old == new:
     return None
   else:
     return list(difflib.unified_diff(
         pprint.pformat(old).splitlines(),
         pprint.pformat(new).splitlines(),
         fromfile='expected', tofile='current',
         n=4, lineterm=''
     ))