$ update-w3c-deps css
# err>   imported/csswg-test/css-ui-3/support/cursors/woolly-64.svgz
# err> Traceback (most recent call last):
# err>   File "/usr/local/google/home/kojii/src/chromium/src/third_party/WebKit/Tools/Scripts/import-w3c-tests", line 35, in <module>
# err>     sys.exit(test_importer.main(sys.argv[1:], sys.stdout, sys.stderr))
# err>   File "/usr/local/google/home/kojii/src/chromium/src/third_party/WebKit/Tools/Scripts/webkitpy/w3c/test_importer.py", line 99, in main
# err>     test_importer.do_import()
# err>   File "/usr/local/google/home/kojii/src/chromium/src/third_party/WebKit/Tools/Scripts/webkitpy/w3c/test_importer.py", line 168, in do_import
# err>     self.import_tests()
# err>   File "/usr/local/google/home/kojii/src/chromium/src/third_party/WebKit/Tools/Scripts/webkitpy/w3c/test_importer.py", line 345, in import_tests
# err>     copied_file = self.copy_file(file_to_copy, dest_dir)
# err>   File "/usr/local/google/home/kojii/src/chromium/src/third_party/WebKit/Tools/Scripts/webkitpy/w3c/test_importer.py", line 415, in copy_file
# err>     host=self.host)
# err>   File "/usr/local/google/home/kojii/src/chromium/src/third_party/WebKit/Tools/Scripts/webkitpy/w3c/test_converter.py", line 63, in convert_for_webkit
# err>     converter.feed(contents.decode('utf-16'))
# err>   File "/usr/lib/python2.7/encodings/utf_16.py", line 16, in decode
# err>     return codecs.utf_16_decode(input, errors, True)
# err> UnicodeDecodeError: 'utf16' codec can't decode bytes in position 34-35: illegal encoding

Probably if new svgz files were added to csswg-test, we fail?

I found:
https://codereview.chromium.org/2539753002/
landed and:
https://codereview.chromium.org/2536163002/
didn't land. I'll look into comments in these CLs later, but any insights if any are appreciated.