W3C test_converter.py fails to prefix if previous declaration does not have ";"

W3C test_converter.py fails to prefix if previous declaration does not have ";"

When test_converter.py started to prefix values, it assumed that there will be
a ";" to end the declaration. This isn't the case if invalid syntax, or when
the property name appear in comments.

Since all cases it handles today is a sipmle single value, this patch changes
the regex to find a word, instead of all text up to ";".

This change fixes the following tests:
  imported/csswg-test/css-writing-modes-3/line-box-direction-019.xht
  imported/csswg-test/css-writing-modes-3/line-box-direction-020.xht

BUG=492664
TEST=Tools/Scripts/webkitpy/w3c/test_converter_unittest.py

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=196490

[kojii, 2015-06-04 07:13:59]

kojii@chromium.org changed reviewers:
+ dpranke@chromium.org, joelo@chromium.org, jsbell@chromium.org,
tkent@chromium.org

[kojii, 2015-06-04 07:13:59]

PTAL.

[tkent, 2015-06-04 07:19:23]

lgtm

[kojii, 2015-06-04 10:53:57]

The CQ bit was checked by kojii@chromium.org

[commit-bot: I haz the power, 2015-06-04 10:54:12]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1162333004/1

[commit-bot: I haz the power, 2015-06-04 10:57:11]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=196490

[Dirk Pranke, 2015-06-04 20:31:58]

lgtm