CSS Tokenizer: Fix handling of escaped newlines

CSS Tokenizer: Fix handling of escaped newlines

This patch fixes our handling of escaped newlines in the css-syntax
tokenizer. Since we don't perform preprocessing, the logic is slightly
trickier than in the spec. The preprocessing replaces \r, \r\n, \f with
\n.

Regarding escaped newlines in strings, the spec states:
"Otherwise, if the next input code point is a newline, consume it."
In this case, we may need to consume two tokens if we have \r\n.

The other cases don't require special handling, since \r\n starts with
\r (also a newline) and in these cases the following token is just going
to be a whitespace token.

BUG=424988
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=184347

[Timothy Loh, 2014-10-24 07:00:56]

timloh@chromium.org changed reviewers:
+ yoav@yoav.ws

[Yoav Weiss, 2014-10-24 07:17:33]

On 2014/10/24 07:01:13, Timothy Loh wrote:

LGTM

[Timothy Loh, 2014-10-24 09:25:24]

The CQ bit was checked by timloh@chromium.org

[commit-bot: I haz the power, 2014-10-24 09:25:38]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/656033010/1

[commit-bot: I haz the power, 2014-10-24 11:14:05]

Committed patchset #1 (id:1) as 184347