This removes the `grid` prefix from the gap-related properties of grid since they are now part of the box alignment specification. Former grid-gap* properties were aliased to the unprefixed properties to maintain compatibility.
The previously multi-column layout only `column-gap` property has been modified to apply to the Grid layout (and Flexbox in a following commit), moving the `mColumnGap` member variable from `nsStyleColumn` to `nsStylePosition`.
Notes:
* Bug 1398537 - support for percent values in column-gap for multi-column layout landed as part of Issue #1230. However, it was incomplete because it did not update `nsRuleNode` to allow transformation of percentage values for `column-gap`. This was consequently fixed as part of this commit.
* Bug 1456166 - this might not apply because we don't have that devtools test in UXP
* `nsRuleNode`, `nsCSSParser`, `Declaration`, and other related classes were merged into Stylo. These should be taken into consideration when porting patches from Mozilla.
Partially based on https://bugzilla.mozilla.org/show_bug.cgi?id=1398482
While we do fail a couple of tests, the other mainstream browsers also fail them and I think our implementation of tab-size is good enough to be unprefixed at this point. Having this patch also makes testing easier.
This CSS property allows input carets (that blinking input cursor you see in text fields), to be given a custom color. This was implemented in Firefox 53, and it was such a minor feature that no one ever missed it, but I don't see any harm in implementing this.
https://bugzilla.mozilla.org/show_bug.cgi?id=1063162
This stub is added because websites insist on considering this
very hardware-dependent and O.S.-variable low-level font-control
as a "critical feature" which it isn't as there is 0 guarantee
that font variation settings are supported or honored by any
operating system used by the client.
On top this is a WD status feature that sites shouldn't be using, and
the feature itself is strongly discouraged for use in favor of standard
CSS font manipulation keywords like `font-weight`.
