Fix unicode rendering of IDL files in the extension/apps developer server.

chrome/common/extensions/docs/server2/local_file_system.py

 # Copyright (c) 2012 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 os
 
 import file_system
 from future import Future
 
 class LocalFileSystem(file_system.FileSystem):
   """FileSystem implementation which fetches resources from the local
   filesystem.
   """
   def __init__(self, base_path):
     self._base_path = self._ConvertToFilepath(base_path)
 
   def _ConvertToFilepath(self, path):
     return path.replace('/', os.sep)
 
   def _ReadFile(self, filename, binary):
     try:
       mode = 'rb' if binary else 'r'
       with open(os.path.join(self._base_path, filename), mode) as f:
         contents = f.read()
         if binary:
           return contents
-        return file_system._ProcessFileData(contents, filename)
+        return file_system._ToUnicode(contents)
     except IOError:
       raise file_system.FileNotFoundError(filename)
 
   def _ListDir(self, dir_name):
     all_files = []
     full_path = os.path.join(self._base_path, dir_name)
     try:
       files = os.listdir(full_path)
     except OSError:
       raise file_system.FileNotFoundError(dir_name)
@@ skipping 21 matching lines @@
                       for filename in os.listdir(path))
     else:
       versions = None
     return file_system.StatInfo(os.stat(path).st_mtime, versions)
 
   def Stat(self, path):
     try:
       return self._CreateStatInfo(os.path.join(self._base_path, path))
     except OSError:
       raise file_system.FileNotFoundError(path)