Support converting utf-16 files when importing w3c tests.

third_party/WebKit/Tools/Scripts/webkitpy/w3c/test_converter.py

 # Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 #
 # 1. Redistributions of source code must retain the above
 #    copyright notice, this list of conditions and the following
 #    disclaimer.
 # 2. Redistributions in binary form must reproduce the above
@@ skipping 29 matching lines @@
     """Converts a file's contents so the Blink layout test runner can run it.
 
     Returns:
       A pair: the list of modified properties, and the modified text if the file was modified, None otherwise.
     """
     contents = host.filesystem.read_binary_file(filename)
     converter = _W3CTestConverter(new_path, filename, reference_support_info, host)
     if filename.endswith('.css'):
         return converter.add_webkit_prefix_to_unprefixed_properties(contents.decode('utf-8'))
     else:
-        converter.feed(contents.decode('utf-8'))
+        try:
+            converter.feed(contents.decode('utf-8'))
+        except UnicodeDecodeError:
+            converter.feed(contents.decode('utf-16'))
         converter.close()
         return converter.output()
 
 
 class _W3CTestConverter(HTMLParser):
     """A HTMLParser subclass which converts a HTML file as it is parsed.
 
     After the feed() method is called, the converted document will be stored
     in converted_data, and can be retrieved with the output() method.
     """
@@ skipping 147 matching lines @@
         self.converted_data.extend(['&#', name, ';'])
 
     def handle_comment(self, data):
         self.converted_data.extend(['<!-- ', data, ' -->'])
 
     def handle_decl(self, decl):
         self.converted_data.extend(['<!', decl, '>'])
 
     def handle_pi(self, data):
         self.converted_data.extend(['<?', data, '>'])