This parsing is hidden behind the pref layout.css.page-size.enabled.
It isn't ideal that we parse this as a property, but we can't treat it as a
descriptor because of compatibility issues with other browsers. There are also
outstanding spec issues related to how descriptors like page-size are cascaded,
and whether the !important specifier is valid or not.
Differential Revision: https://phabricator.services.mozilla.com/D103958
To know the valid rules for each property, we need to put this information
into the Servo prop list and add an appropriate getter to Longhand/Shorthand.
Differential Revision: https://phabricator.services.mozilla.com/D105825
This parsing is hidden behind the pref layout.css.page-size.enabled.
It isn't ideal that we parse this as a property, but we can't treat it as a
descriptor because of compatibility issues with other browsers. There are also
outstanding spec issues related to how descriptors like page-size are cascaded,
and whether the !important specifier is valid or not.
Differential Revision: https://phabricator.services.mozilla.com/D103958
To know the valid rules for each property, we need to put this information
into the Servo prop list and add an appropriate getter to Longhand/Shorthand.
Differential Revision: https://phabricator.services.mozilla.com/D105825
Starting with macOS 10.14, the generic light/dark vibrancy is deprecated, and semantic vibrancy names are preferred.
If we ever need more vibrancy, we can add new values with semantic names.
Depends on D107910
Differential Revision: https://phabricator.services.mozilla.com/D108152
The reason why this doesn't work is because these styles come from
datetimebox.css, which is really an author style.
We could special-case these elements, but the approach that the CSSWG resolved
on for the new forced-colors spec is to respect system colors specified by
authors, see:
https://drafts.csswg.org/css-color-adjust-1/#forced-colors-properties
So this moves us towards that, and fixes the issue nicely.
Differential Revision: https://phabricator.services.mozilla.com/D108321
This parsing is hidden behind the pref layout.css.page-size.enabled.
It isn't ideal that we parse this as a property, but we can't treat it as a
descriptor because of compatibility issues with other browsers. There are also
outstanding spec issues related to how descriptors like page-size are cascaded,
and whether the !important specifier is valid or not.
Differential Revision: https://phabricator.services.mozilla.com/D103958
To know the valid rules for each property, we need to put this information
into the Servo prop list and add an appropriate getter to Longhand/Shorthand.
Differential Revision: https://phabricator.services.mozilla.com/D105825
And remove the windows-specific versions of this color.
Also fix the hard-coded defaults by the colors I get in the default windows
theme.
Differential Revision: https://phabricator.services.mozilla.com/D108325
This will allow us to not change these files if we need to change the
rayon version to fix stability issues like bug 1694671.
Differential Revision: https://phabricator.services.mozilla.com/D108042
This should be both a memory and speed win for pages using a lot of
Shadow DOM.
In order to make the cache properly work we need to start keying media query
results on the actual StyleSheetContents, as that's what we share on Gecko, but
that should all be fine.
Differential Revision: https://phabricator.services.mozilla.com/D107266
It was clarified that the percentages are weights, and two weights are
now allowed. Missing percentages are computed as 100% - the other or
50%. Other than that, commas are required etc, which is good since
that's how I implemented it originally.
Differential Revision: https://phabricator.services.mozilla.com/D107295
This is straight-forward and builds on the color animation code. This
implements only the <percentage> syntax, not the whole <color-adjuster>
syntax, which seems fairly more complex.
Of course, this only uses sRGB because that's all the colors we support,
but it should be feasible to extend to lab() / lch() colors once we
support those.
I believe this subset of syntax is useful and worth implementing, so
people can play with it and say if it's useful.
Differential Revision: https://phabricator.services.mozilla.com/D106698
This will prevent growing them when introducing fit-content(<length>).
This can _almost_ be derived, if it wasn't because of the quirky stuff.
I think the macro is probably good enough for now but let me know if you
disagree.
Differential Revision: https://phabricator.services.mozilla.com/D106713
This will prevent growing them when introducing fit-content(<length>).
This can _almost_ be derived, if it wasn't because of the quirky stuff.
I think the macro is probably good enough for now but let me know if you
disagree.
Differential Revision: https://phabricator.services.mozilla.com/D106713
I also update the wpt becasue it seems the original one lets <ratio>
support the addition. However, the spec says "Addition of <ratio>s is not
possible".
Differential Revision: https://phabricator.services.mozilla.com/D106219
And alias :-moz-ui-valid and :-moz-ui-invalid to them.
There are CSSWG resolutions for these for quite a while, and spec for
user-invalid.
Differential Revision: https://phabricator.services.mozilla.com/D105966
No other browser supports anything like this and we don't even have
internal users. Only uses of this I've found on the wild were just
resetting the box shadow internal styling we added in bug 582277 (and
since removed in bug 600151).
Differential Revision: https://phabricator.services.mozilla.com/D105955
This reduces the amount of assembly instructions generated by this
function from 18k+ to ~800.
This should make reasoning about its stack space usage sane, and should
fix the ASAN stack overflows, but also we should take this regardless,
because it's saner and makes reading it simpler.
I also think that the writing_mode shenanigans is fixing a bug (I think
before this, we'd pick the first physical value which mapped to any of
the properties, which is wrong), but I haven't bothered looking for a
test-case that fails before my patch. The relevant WPTs
(css/css-logical/animation*) still pass.
Differential Revision: https://phabricator.services.mozilla.com/D105342
This brings the time down to 1.6ms from 4.8ms on the test-case in the
bug. This should be improvable too, but I think this is a nice
improvement for regular styling as well.
Differential Revision: https://phabricator.services.mozilla.com/D105187
This doesn't use a full bitmap for every single rule type, as we only expect
that keyframe, page, and style rules will be checked.
Differential Revision: https://phabricator.services.mozilla.com/D104949
This brings the time down to 1.6ms from 4.8ms on the test-case in the
bug. This should be improvable too, but I think this is a nice
improvement for regular styling as well.
Differential Revision: https://phabricator.services.mozilla.com/D105187
Actually, there's not so much we can improve right now, in the sense
that:
* We need the ::-moz-page-content pseudo-element to be able to set
`display` on the page, since that's a style rule rather than a @page
rule. We could get away without it.
* Keeping the current code-path (slightly cleaned up) is less code, for
now at least. We can have a separate code-path or what not that
actually performs the @page rule selector-matching and what not if
needed when we get to named pages or other page selectors. Selectors
like :first should be pretty trivial to implement, actually.
We make some paged mode anon boxes non-inheriting anon boxes. This
allows us to share the styles and is generally nicer. They don't need to
inherit from anywhere.
We could remove the origin handling and don't look at UA rules or what
not, but it seems pretty harmless to do that.
We also fix the name of the pseudo-elements to match the capitalization.
Differential Revision: https://phabricator.services.mozilla.com/D104772
Actually, there's not so much we can improve right now, in the sense
that:
* We need the ::-moz-page-content pseudo-element to be able to set
`display` on the page, since that's a style rule rather than a @page
rule. We could get away without it.
* Keeping the current code-path (slightly cleaned up) is less code, for
now at least. We can have a separate code-path or what not that
actually performs the @page rule selector-matching and what not if
needed when we get to named pages or other page selectors. Selectors
like :first should be pretty trivial to implement, actually.
We make some paged mode anon boxes non-inheriting anon boxes. This
allows us to share the styles and is generally nicer. They don't need to
inherit from anywhere.
We could remove the origin handling and don't look at UA rules or what
not, but it seems pretty harmless to do that.
We also fix the name of the pseudo-elements to match the capitalization.
Differential Revision: https://phabricator.services.mozilla.com/D104772
Some GTK themes use very soft colors for selection backgrounds, using
darker colors for the text. This makes the tab and focus outlines in the
tab bar not have sufficient contrast with usual backgrounds.
I needed to do this for bug 1690778, but it seems worth doing it on the
front-end as well.
Differential Revision: https://phabricator.services.mozilla.com/D104547
It's only used to disambiguate between the one-argument and the trait
version of Keyword::parse. Instead, just explicitly use the trait
version, so that we don't need to specify it.
Differential Revision: https://phabricator.services.mozilla.com/D104328
It's only used to disambiguate between the one-argument and the trait
version of Keyword::parse. Instead, just explicitly use the trait
version, so that we don't need to specify it.
Differential Revision: https://phabricator.services.mozilla.com/D104328
This shipped in 85, we can remove the feature flag now. Keep
:-moz-focusring as an alias to :focus-visible at parse time.
Differential Revision: https://phabricator.services.mozilla.com/D103752
This shipped in 85, we can remove the feature flag now. Keep
:-moz-focusring as an alias to :focus-visible at parse time.
Differential Revision: https://phabricator.services.mozilla.com/D103752
There's no reason we should need an scrollbar box to query the size of a
scrollbar. I plan to use this in the following patch to make the size of a
resizer not vary depending on whether the container has scrollbars or not,
which is what ultimately causes the reftest failure.
Differential Revision: https://phabricator.services.mozilla.com/D103302
We add two @-moz-document functions: `plain-text-document()`, matching the
obvious, and `unobservable-document()`, which matches a top-level document with
no opener. This is the equivalent check we do for automatic darkening of
`about:blank` here:
https://searchfox.org/mozilla-central/rev/014fe72eaba26dcf6082fb9bbaf208f97a38594e/layout/base/PresShell.cpp#5282
The former we don't need to use, but it's nice to let user stylesheets target
plaintext documents properly (rather than relying on extensions or what not).
Note that these are not content-observable.
Add two tests: One showing that we produce different rendering when on dark
mode, and one showing that we produce the same one from an iframe, regardless
of dark mode.
Depends on D101517
Differential Revision: https://phabricator.services.mozilla.com/D101518
We add two @-moz-document functions: `plain-text-document()`, matching the
obvious, and `unobservable-document()`, which matches a top-level document with
no opener. This is the equivalent check we do for automatic darkening of
`about:blank` here:
https://searchfox.org/mozilla-central/rev/014fe72eaba26dcf6082fb9bbaf208f97a38594e/layout/base/PresShell.cpp#5282
The former we don't need to use, but it's nice to let user stylesheets target
plaintext documents properly (rather than relying on extensions or what not).
Note that these are not content-observable.
Add two tests: One showing that we produce different rendering when on dark
mode, and one showing that we produce the same one from an iframe, regardless
of dark mode.
Depends on D101517
Differential Revision: https://phabricator.services.mozilla.com/D101518
We add two @-moz-document functions: `plain-text-document()`, matching the
obvious, and `unobservable-document()`, which matches a top-level document with
no opener. This is the equivalent check we do for automatic darkening of
`about:blank` here:
https://searchfox.org/mozilla-central/rev/014fe72eaba26dcf6082fb9bbaf208f97a38594e/layout/base/PresShell.cpp#5282
The former we don't need to use, but it's nice to let user stylesheets target
plaintext documents properly (rather than relying on extensions or what not).
Note that these are not content-observable.
Add two tests: One showing that we produce different rendering when on dark
mode, and one showing that we produce the same one from an iframe, regardless
of dark mode.
Depends on D101517
Differential Revision: https://phabricator.services.mozilla.com/D101518
We add two @-moz-document functions: `plain-text-document()`, matching the
obvious, and `unobservable-document()`, which matches a top-level document with
no opener. This is the equivalent check we do for automatic darkening of
`about:blank` here:
https://searchfox.org/mozilla-central/rev/014fe72eaba26dcf6082fb9bbaf208f97a38594e/layout/base/PresShell.cpp#5282
The former we don't need to use, but it's nice to let user stylesheets target
plaintext documents properly (rather than relying on extensions or what not).
Note that these are not content-observable.
Add two tests: One showing that we produce different rendering when on dark
mode, and one showing that we produce the same one from an iframe, regardless
of dark mode.
Depends on D101517
Differential Revision: https://phabricator.services.mozilla.com/D101518
The only way that this can happen is if we get through the
ShouldTreatAsCompleteDueToSyncDecode check returning true in the case of
the image being errored.
https://hg.mozilla.org/integration/autoland/rev/645a4d6461ca was
supposed to deal with this, but my guess is that there is a slight race
condition in which the error status isn't there at the beginning, but is
there after the StartDecoding call.
It seems returning BAD_IMAGE rather than painting transparent if we hit
a broken image is a better thing to do than what we're doing now, and
should fix the intermittent issue.
Differential Revision: https://phabricator.services.mozilla.com/D101361
This is based on the logic in ResponsiveImageSelector::SelectImage (just
simplified because there's no viewport-dependent widths here).
Differential Revision: https://phabricator.services.mozilla.com/D100698
This allows supporting image-set(), etc, and simplifies the bullet frame
code significantly, too thanks to two changes:
* Instead of manually managing the image request, use the CSS image
loader, with the `REQUEST_REQUIRES_REFLOW` flag, to handle image
loads correctly. This didn't exist when this code was initially
implemented, but we can nicely use it now.
* Instead of re-implementing another WebRender command-builder thing,
we can just reuse the nsImageRenderer code.
Differential Revision: https://phabricator.services.mozilla.com/D100774
This implements the basic image-set notation without the format()
function (for simplicity).
There's a remaining serialization issue (we should probably skip 1x
resolutions), but that's fine for now, I'll address this in a follow-up
when the feature is testable.
The intention is to do the image selection at computed value time
(keeping a selected index or such), but same, follow-up.
This also fixes an issue where the cors-mode for -moz-image-rect and
cross-fade() was getting ignored when parsing.
Differential Revision: https://phabricator.services.mozilla.com/D100640
This allows supporting image-set(), etc, and simplifies the bullet frame
code significantly, too thanks to two changes:
* Instead of manually managing the image request, use the CSS image
loader, with the `REQUEST_REQUIRES_REFLOW` flag, to handle image
loads correctly. This didn't exist when this code was initially
implemented, but we can nicely use it now.
* Instead of re-implementing another WebRender command-builder thing,
we can just reuse the nsImageRenderer code.
Differential Revision: https://phabricator.services.mozilla.com/D100774
These are never empty, and storing 4 elements inline seems worth it
given we also heap-allocate the array itself.
Depends on D100592
Differential Revision: https://phabricator.services.mozilla.com/D100593
Based on the spec, if the aspect-ratio property value is:
1) auto: we should always use content-box dimensions.
2) <ratio>: the aspect-ratio works with box sizing dimensions.
3) auto && <ratio>: we use content-box dimensions in all cases.
So we need an extra flag to address that we should use box-sizing or
always use content-box dimensions while computing the size in
ratio-dependent axis.
This also updates some wpts for non-replaced elements because we should
use content-box if aspect-ratio is 'auto && <ratio>'.
Differential Revision: https://phabricator.services.mozilla.com/D100072
This lifts a bunch of string conversions higher up the stack, but allows
us to make the servo code use utf-8 unconditionally, and seemed faster
in my benchmarking (see comment 0).
It should also make a bunch of attribute setters faster too (like
setting .cssText), now that we use UTF8String for them (we couldn't
because we couldn't specify different string types for the getter and
setters).
Differential Revision: https://phabricator.services.mozilla.com/D99590
We unshipped these a while ago and left the pref just for testing
purposes. But now all the reftests using it were conveniently migrated
to chrome:// tests, so we no longer need it.
Differential Revision: https://phabricator.services.mozilla.com/D56950
The changes should be trivial.
The third_party changes are up for review in
https://github.com/servo/rust-cssparser/pull/277 (and of course I'll
land with a bump to 0.28 rather than the override after that gets r+'d).
The basic idea is that with this we have the actual start offset of the
rule, so we wouldn't include html comments or other invalid stuff we
discard during sanitization in bug 1680084. But that's a separate
change.
Differential Revision: https://phabricator.services.mozilla.com/D98677
The changes should be trivial.
The third_party changes are up for review in
https://github.com/servo/rust-cssparser/pull/277 (and of course I'll
land with a bump to 0.28 rather than the override after that gets r+'d).
The basic idea is that with this we have the actual start offset of the
rule, so we wouldn't include html comments or other invalid stuff we
discard during sanitization in bug 1680084. But that's a separate
change.
Differential Revision: https://phabricator.services.mozilla.com/D98677
We add a new file, AspectRatio.cpp, to definte the method,
ComputeRatioDependentSize. So we don't have to move this function to
WritingModes.h
Besides, we miss the forward declaration of IPC::ParamTraits, so add it
into AspectRatio.h.
Differential Revision: https://phabricator.services.mozilla.com/D95822
The browser currently only enables plugin behavior for Flash and our internal test plugins. This patch replaces support for those plugins with a simple fallback that shows a transparent region where the plugin would have been. It removes the file system search(es) for the plugin dynamic libraries and short-circuits the logic to determine if plugins should do something special -- all implementations now behave the same in the presence of plugin elements.
The new behavior is:
1. If the <object> or <embed> element lists a type of something other than "x-shockwave-flash" or "x-test" then the behavior is unchanged. This means that non-plugin types behave properly and unknown types (for example, typos) are also unaffected (they reduce to 0x0 elements).
2. If the <object> element has an HTML fallback in the DOM (see spec for <object> elements) then the fallback is always shown.
3. Otherwise, the element is shown as a transparent region with the size specified in attributes.
Differential Revision: https://phabricator.services.mozilla.com/D95902
The browser currently only enables plugin behavior for Flash and our internal test plugins. This patch replaces support for those plugins with a simple fallback that shows a transparent region where the plugin would have been. It removes the file system search(es) for the plugin dynamic libraries and short-circuits the logic to determine if plugins should do something special -- all implementations now behave the same in the presence of plugin elements.
The new behavior is:
1. If the <object> or <embed> element lists a type of something other than "x-shockwave-flash" or "x-test" then the behavior is unchanged. This means that non-plugin types behave properly and unknown types (for example, typos) are also unaffected (they reduce to 0x0 elements).
2. If the <object> element has an HTML fallback in the DOM (see spec for <object> elements) then the fallback is always shown.
3. Otherwise, the element is shown as a transparent region with the size specified in attributes.
Differential Revision: https://phabricator.services.mozilla.com/D95902
The spec text has been improved a while ago, so I think we should do
this. This keeps the current moz-focusring behavior when the pref is
disabled, but when enabled it becomes effectively an alias of
focus-visible.
Differential Revision: https://phabricator.services.mozilla.com/D96697
New versions have shrink_to_fit(). This also explicitly requests the
"std" feature, because otherwise autocfg fails to pass the panic=abort
flag to rustc and it chokes.
Depends on D96130
Differential Revision: https://phabricator.services.mozilla.com/D96131
In order to determine whether classes or ids are case insensitive we
need the document quirks mode. The sheet quirks mode almost always
matches, but may not match when sheets are added by privileged APIs.
Differential Revision: https://phabricator.services.mozilla.com/D95061
This fixes the failures in bug 1671573 and just works thanks to the
invalidation improvements I did for :is / :where.
Added a couple tests for invalidation which is the tricky bit. 001 is a
very straight-forward test, 002 is the :is test but with :is() replaced
by double-:not().
This also fixes default namespaces inside :is() / :where(), which are
supposed to get ignored, but aren't. Added tests for that and for the
pre-existing :not() behavior which Chrome doesn't quite get right.
Differential Revision: https://phabricator.services.mozilla.com/D94142
Allow-list all Python code in tree for use with the black linter, and re-format all code in-tree accordingly.
To produce this patch I did all of the following:
1. Make changes to tools/lint/black.yml to remove include: stanza and update list of source extensions.
2. Run ./mach lint --linter black --fix
3. Make some ad-hoc manual updates to python/mozbuild/mozbuild/test/configure/test_configure.py -- it has some hard-coded line numbers that the reformat breaks.
4. Make some ad-hoc manual updates to `testing/marionette/client/setup.py`, `testing/marionette/harness/setup.py`, and `testing/firefox-ui/harness/setup.py`, which have hard-coded regexes that break after the reformat.
5. Add a set of exclusions to black.yml. These will be deleted in a follow-up bug (1672023).
# ignore-this-changeset
Differential Revision: https://phabricator.services.mozilla.com/D94045
Allow-list all Python code in tree for use with the black linter, and re-format all code in-tree accordingly.
To produce this patch I did all of the following:
1. Make changes to tools/lint/black.yml to remove include: stanza and update list of source extensions.
2. Run ./mach lint --linter black --fix
3. Make some ad-hoc manual updates to python/mozbuild/mozbuild/test/configure/test_configure.py -- it has some hard-coded line numbers that the reformat breaks.
4. Make some ad-hoc manual updates to `testing/marionette/client/setup.py`, `testing/marionette/harness/setup.py`, and `testing/firefox-ui/harness/setup.py`, which have hard-coded regexes that break after the reformat.
5. Add a set of exclusions to black.yml. These will be deleted in a follow-up bug (1672023).
# ignore-this-changeset
Differential Revision: https://phabricator.services.mozilla.com/D94045
Allow-list all Python code in tree for use with the black linter, and re-format all code in-tree accordingly.
To produce this patch I did all of the following:
1. Make changes to tools/lint/black.yml to remove include: stanza and update list of source extensions.
2. Run ./mach lint --linter black --fix
3. Make some ad-hoc manual updates to python/mozbuild/mozbuild/test/configure/test_configure.py -- it has some hard-coded line numbers that the reformat breaks.
4. Add a set of exclusions to black.yml. These will be deleted in a follow-up bug (1672023).
# ignore-this-changeset
Differential Revision: https://phabricator.services.mozilla.com/D94045
Otherwise on Windows, we have a ColorID::Scrollbar but not any of the other scrollbar part
colors, and the Windows-provided value for Scrollbar doesn't work well
with the default values for the other scrollbar parts that come from the
non-native theme.
Differential Revision: https://phabricator.services.mozilla.com/D93728
Based on the update of github.com/w3c/csswg-drafts/issues/5084,
a 0/0 ratio will serialize as 0/0 in all value stages.
Differential Revision: https://phabricator.services.mozilla.com/D93182
Which allows to run CSS.supports in chrome/user-agent context. We should
probably add a couple more tweaks for stuff like quirks or what not (the
`ParsingMode` enum), but that seem lower priority.
I only added the one-value version of CSS.supports because it should be enough
and supporting the two value version required a bit of awkward code due to when
we parse the CSS property name right now.
Differential Revision: https://phabricator.services.mozilla.com/D92585
So that skip_children(), which just pops the stack and is used by the
dynamic media query evaluation code, works as it should.
Differential Revision: https://phabricator.services.mozilla.com/D92717
The math-depth implementation is refined to take into account the
ScriptPercentScaleDown and ScriptScriptPercentScaleDown constants (if the
parent's first valid font has a MATH table) in order to calculate the
scale factor between math-deth 0 and 1, and between 0 and 2 respectively.
Behavior is unchanged if the legacy scriptsizemultiplier attribute is
specified or if no MATH table is available.
The preference layout.css.math-depth.enabled remains disabled in nightly
until the remaining bit (support for font-size: math) is implemented in
bug 1667090.
Differential Revision: https://phabricator.services.mozilla.com/D91604
But discard it when backplating behind text, so that text is readable.
This should be uncontroversial... Dealing with widgets is a bit harder
so TBD.
Differential Revision: https://phabricator.services.mozilla.com/D91779
But discard it when backplating behind text, so that text is readable.
This should be uncontroversial... Dealing with widgets is a bit harder
so TBD.
Differential Revision: https://phabricator.services.mozilla.com/D91779
This renames the internal -moz-math-script-level property in order to
prepare for full math-depth support. Currently, the property is guarded
under a disabled-by-default flag, so there should be no observable
behavior change.
Differential Revision: https://phabricator.services.mozilla.com/D91285
This renames the internal -moz-math-script-level property in order to
prepare for full math-depth support. Currently, the property is guarded
under a disabled-by-default flag, so there should be no observable
behavior change.
Differential Revision: https://phabricator.services.mozilla.com/D91285
This renames the internal -moz-math-script-level property in order to
prepare for full math-depth support. Currently, the property is guarded
under a disabled-by-default flag, so there should be no observable
behavior change.
Differential Revision: https://phabricator.services.mozilla.com/D91285
This renames the internal -moz-math-script-level property in order to
prepare for full math-depth support. Currently, the property is guarded
under a disabled-by-default flag, so there should be no observable
behavior change.
Differential Revision: https://phabricator.services.mozilla.com/D91285
This patch renames the internal -moz-math-display to math-style and
exposes it under the layout.css.math-style.enabled preference. The
initial value becomes "normal" but that does not affect the default
MathML behavior since the UA style sheet sets the math-style property
explicitly on <math> tags. WPT tests are updated to use the syntax
approved by the CSSWG.
Intent to prototype: https://groups.google.com/forum/#!msg/mozilla.dev.platform/1hQQ7ISudGo/_yLEckEeBQAJ
Differential Revision: https://phabricator.services.mozilla.com/D90731
This patch renames the internal -moz-math-display to math-style and
exposes it under the layout.css.math-style.enabled preference. The
initial value becomes "normal" but that does not affect the default
MathML behavior since the UA style sheet sets the math-style property
explicitly on <math> tags. WPT tests are updated to use the syntax
approved by the CSSWG.
Intent to prototype: https://groups.google.com/forum/#!msg/mozilla.dev.platform/1hQQ7ISudGo/_yLEckEeBQAJ
Differential Revision: https://phabricator.services.mozilla.com/D90731
This patch renames the internal -moz-math-display to math-style and
exposes it under the layout.css.math-style.enabled preference. The
initial value becomes "normal" but that does not affect the default
MathML behavior since the UA style sheet sets the math-style property
explicitly on <math> tags. WPT tests are updated to use the syntax
approved by the CSSWG.
Intent to prototype: https://groups.google.com/forum/#!msg/mozilla.dev.platform/1hQQ7ISudGo/_yLEckEeBQAJ
Differential Revision: https://phabricator.services.mozilla.com/D90731
