This removes the need to keep the `flex-basis` handling code of the ComputeSize* functions in sync since they both call the same function now for this purpose.
This implements flexbox layout for the gap properties without the refactoring work performed on `nsFlexContainerFrame`.
Partially based on https://bugzilla.mozilla.org/show_bug.cgi?id=1398483 and https://bugzilla.mozilla.org/show_bug.cgi?id=1454822
This excludes the second part of bug 1454822, the width caching implementation, because it is out of scope and currently causes unstable layout with `writing-mode: vertical-lr` (see bug 1709937).
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
A very very old bug and annoyance: tooltips with very long content without
spaces (e.g. long URLs or gibberish data) would just cut off and leave an
un-styled right border going over the widget's constrained space.
Because of an additional bug (still unsolved), this was never properly
addressed because solutions attempted didn't work.
The workaround for the secondary bug allows for word-break to now work and this
primary problem to be resolved.
Apparently Bing does rapid-fire loading/unloading of module scripts that causes
our attempts at resolving and initializing them to end up with null fetched
modules. Returning null is probably a better way to handle this than crashing
on ms->ModuleRecord().
This restores support for using HTML tag styling of margins on the body.
Reftests post bug still pass for dynamic changes, so does the newly-added
test for body margins and frames that tests the old styling method.
This also removes the reftest list for stylo testing for obvious reasons.
