[CSS Grid Layout] Fix grid-template-areas parsing to avoid spaces

[CSS Grid Layout] Fix grid-template-areas parsing to avoid spaces

The spec doesn't require to have spaces between unnamed and named areas
in grid-template-areas syntax. But spaces are currently required in our
code.

This was confirmed in the CSS WG mailing list:
https://lists.w3.org/Archives/Public/www-style/2015May/0239.html

This patch updates grid-template-areas parsing to allow the possibility
of removing spaces between unnamed and named areas.

Added new case to fast/css-grid-layout/grid-template-areas-get-set.html.

BUG=490088
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=196901

[Manuel Rego, 2015-06-10 11:38:22]

rego@igalia.com changed reviewers:
+ dsinclair@chromium.org, jchaffraix@chromium.org, svillar@igalia.com,
timloh@chromium.org

[Julien - ping for review, 2015-06-10 15:31:18]

lgtm

https://codereview.chromium.org/1178503003/diff/1/Source/core/css/parser/CSSP...
File Source/core/css/parser/CSSPropertyParser.cpp (right):

https://codereview.chromium.org/1178503003/diff/1/Source/core/css/parser/CSSP...
Source/core/css/parser/CSSPropertyParser.cpp:3679: StringImpl& text =
*gridRowNames.impl();
I would like a comment for this. I assume this is because you want to avoid
NULL-checking the StringImpl all the time in WTFString::operator[].

https://codereview.chromium.org/1178503003/diff/1/Source/core/css/parser/CSSP...
Source/core/css/parser/CSSPropertyParser.cpp:3681: String areaName = "";
You want to use StringBuilder to avoid unneeded buffer copies, which will kill
performance.

[Manuel Rego, 2015-06-10 20:41:45]

Thanks for the review.

Upload new rebased patch applied suggested changes.

https://codereview.chromium.org/1178503003/diff/1/Source/core/css/parser/CSSP...
File Source/core/css/parser/CSSPropertyParser.cpp (right):

https://codereview.chromium.org/1178503003/diff/1/Source/core/css/parser/CSSP...
Source/core/css/parser/CSSPropertyParser.cpp:3679: StringImpl& text =
*gridRowNames.impl();
On 2015/06/10 15:31:18, Julien Chaffraix - PST wrote:
> I would like a comment for this. I assume this is because you want to avoid
> NULL-checking the StringImpl all the time in WTFString::operator[].

Yes. Added a comment.

https://codereview.chromium.org/1178503003/diff/1/Source/core/css/parser/CSSP...
Source/core/css/parser/CSSPropertyParser.cpp:3681: String areaName = "";
On 2015/06/10 15:31:18, Julien Chaffraix - PST wrote:
> You want to use StringBuilder to avoid unneeded buffer copies, which will kill
> performance.

Done.

[Manuel Rego, 2015-06-10 20:41:50]

The CQ bit was checked by rego@igalia.com

[Manuel Rego, 2015-06-10 20:41:50]

The patchset sent to the CQ was uploaded after l-g-t-m from
jchaffraix@chromium.org
Link to the patchset: https://codereview.chromium.org/1178503003/#ps20001
(title: "Rebased patch applying suggested changes")

[commit-bot: I haz the power, 2015-06-10 20:42:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1178503003/20001

[commit-bot: I haz the power, 2015-06-10 21:49:23]

Committed patchset #2 (id:20001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=196901