This broke lots of layout tests on OSX.

tools/grit/grit/format/data_pack_unittest.py

Index: tools/grit/grit/format/data_pack_unittest.py
===================================================================
--- tools/grit/grit/format/data_pack_unittest.py	(revision 101223)
+++ tools/grit/grit/format/data_pack_unittest.py	(working copy)
@@ -16,17 +16,15 @@
 class FormatDataPackUnittest(unittest.TestCase):
   def testWriteDataPack(self):
     expected = (
-        '\x04\x00\x00\x00'                  # header(version
-        '\x04\x00\x00\x00'                  #        no. entries,
-        '\x01'                              #        encoding)
-        '\x01\x00\x27\x00\x00\x00'          # index entry 1
-        '\x04\x00\x27\x00\x00\x00'          # index entry 4
-        '\x06\x00\x33\x00\x00\x00'          # index entry 6
-        '\x0a\x00\x3f\x00\x00\x00'          # index entry 10
-        '\x00\x00\x3f\x00\x00\x00'          # extra entry for the size of last
+        '\x03\x00\x00\x00\x04\x00\x00\x00'  # header (version, no. entries)
+        '\x01\x00\x26\x00\x00\x00'          # index entry 1
+        '\x04\x00\x26\x00\x00\x00'          # index entry 4
+        '\x06\x00\x32\x00\x00\x00'          # index entry 6
+        '\x0a\x00\x3e\x00\x00\x00'          # index entry 10
+        '\x00\x00\x3e\x00\x00\x00'          # extra entry for the size of last
         'this is id 4this is id 6')         # data
     input = { 1: "", 4: "this is id 4", 6: "this is id 6", 10: "" }
-    output = data_pack.DataPack.WriteDataPackToString(input, data_pack.UTF8)
+    output = data_pack.DataPack.WriteDataPackToString(input)
     self.failUnless(output == expected)