commit 406010c4b4e27073d52f2d7af881a302d1beae99
author Manuel Rego Casasnovas <rego@igalia.com> Mon Feb 05 09:07:10 2018
committer Commit Bot <commit-bot@chromium.org> Mon Feb 05 09:07:10 2018
tree 1f6af4d87cde9cd4066123ceecff8f1e7112aae9
parent 5fb546aaede6dca95bcc170fc681b86061849a18

[css-grid] Unprefix gutter properties

This patch applies the resoultion of the CSS WG to unprefix
the CSS Grid Layout gutter properties:
https://github.com/w3c/csswg-drafts/issues/1696

That is:
* grid-column-gap => column-gap
* grid-row-gap => row-gap
* grid-gap => gap

column-gap already existed before, as it's part of Multicol,
and it already has an alias -webkit-column-gap.
For that reason it's not possible to implement another alias
for grid-column-gap, so it was done with a shorthand.
To follow the same pattern the shorthand approach was used for
grid-row-gap and grid-gap too.

As column-gap was already animatable, this change takes advantage
to make animatable row-gap too.

Intent to Implement and Ship thread:
https://groups.google.com/a/chromium.org/d/msg/blink-dev/UViBfJuuIq8/w7_2W7lLAgAJ

Converted grid-gutters-get-set.html in some WPT tests covering
a few extra cases.
Added WPT test to verify the animation of these properties too.

BUG=761904
TEST=external/wpt/css/css-align/gaps/

Change-Id: If49ec34116eff0b3b745fc89b01b15b14c71d4a9
Reviewed-on: https://chromium-review.googlesource.com/890446
Reviewed-by: Javier Fernandez <jfernandez@igalia.com>
Reviewed-by: Rune Lillesveen <futhark@chromium.org>
Reviewed-by: Kent Tamura <tkent@chromium.org>
Commit-Queue: Manuel Rego Casasnovas <rego@igalia.com>
Cr-Commit-Position: refs/heads/master@{#534351}