This broke lots of layout tests on OSX.

tools/data_pack/repack.py

 #!/usr/bin/python
 # Copyright (c) 2011 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.
 
 """A simple utility function to merge data pack files into a single data pack.
 See base/pack_file* for details about the file format.
 
 TODO(adriansc): Remove this file once the dependency has been updated in WebKit
 to point to grit scripts.
 """
 
 import exceptions
 import struct
 import sys
 
 import data_pack
 
 def RePack(output_file, input_files):
   """Write a new data pack to |output_file| based on a list of filenames
   (|input_files|)"""
   resources = {}
-  encoding = None
   for filename in input_files:
-    new_content = data_pack.ReadDataPack(filename)
+    new_resources = data_pack.ReadDataPack(filename)
 
     # Make sure we have no dups.
-    duplicate_keys = set(new_content.resources.keys()) & set(resources.keys())
+    duplicate_keys = set(new_resources.keys()) & set(resources.keys())
     if len(duplicate_keys) != 0:
       raise exceptions.KeyError("Duplicate keys: " + str(list(duplicate_keys)))
 
-    # Make sure encoding is consistent.
-    if encoding in (None, data_pack.BINARY):
-      encoding = new_content.encoding
-    elif new_content.encoding not in (data_pack.BINARY, encoding):
-        raise exceptions.KeyError("Inconsistent encodings: " +
-                                  str(encoding) + " vs " +
-                                  str(new_content.encoding))
+    resources.update(new_resources)
 
-    resources.update(new_content.resources)
-
-  # Encoding is 0 for BINARY, 1 for UTF8 and 2 for UTF16
-  if encoding is None:
-    encoding = data_pack.BINARY
-  data_pack.WriteDataPack(resources, output_file, encoding)
+  data_pack.WriteDataPack(resources, output_file)
 
 def main(argv):
   if len(argv) < 3:
     print ("Usage:\n  %s <output_filename> <input_file1> [input_file2] ... " %
            argv[0])
     sys.exit(-1)
   RePack(argv[1], argv[2:])
 
 if '__main__' == __name__:
   main(sys.argv)