Fix WHITESPACE issues in the CSS grammar.

Fix WHITESPACE issues in the CSS grammar.

A single WHITESPACE token consumes consecutive spaces, but does not consume
spaces separated by comments. That means S* and S+ in CSS grammars need to
accept multiple WHITESPACE tokens. Additionally, white spaces are not
mandatory to separate an @-symbol and the rest of the prelude.

Use space non-terminal instead of WHITESPACE for S+ in calc expressions.

Use maybe_space non-terminal instead of WHITESPACE for S* after @-webkit-filter
and @-webkit-region.

BUG=303303
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=158950

[apavlov, 2013-10-04 13:49:38]

lgtm

[commit-bot: I haz the power, 2013-10-04 13:49:45]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rune@opera.com/25607005/1

[commit-bot: I haz the power, 2013-10-04 16:44:14]

Retried try job too often on win_blink_rel for step(s) webkit_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_blink_...

[commit-bot: I haz the power, 2013-10-04 17:04:22]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rune@opera.com/25607005/1

[commit-bot: I haz the power, 2013-10-04 17:55:57]

Change committed as 158950