Implement custom element reactions
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Initial work for implementing custom element reactions: https://html.spec.whatwg.org/multipage/custom-elements.html#custom-element-reactions
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This patch also removes the duplication of style contexts during the
restyle, because otherwise pointer equality of ServoComputedValues stops
holding (and we assert on that in a few places)
Some fixes to selector serialization re: namespaces and universal selector
- Fix eliding default namespace when serializing
- Fix shortest serialization property when namespace prefix is `*|` and there is no default namespace
- Omit universal selector when serializing to match `cssom/serialize-namespaced-type-selectors` (again so we get the shortest serialization)
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I'd like to land #17501 first, because it allows some tests for this to work.
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Don't delete webrender image keys immediately.
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We currently delete webrender image id's immediately on resizing a canvas, which can cause panics. This PR delays deleting the image id until an epoch has passed.
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If omitting the universal selector in the serialization is possible, we
should do it so we obtain a shorter serialization (to match the behavior
asserted in cssom/serialize-namespaced-type-selectors.html).
For example, if someone writes *|*::before and there is no default
namespace, we should serialize to ::before; however, if there is a
default namespace, we should serialize to *|*::before.
(This is the test case "Universal selector in any namespace followed by
pseudo element).
This matches the behavior implemented by WebKit; that one case in
particular isn't implemented by Gecko, but other cases where the
universal selector should be elided are implemented by Gecko but were not
previously by Servo.
Once again it seems we don't need to preserve the original prefix name,
and this lets to_css serialize to the shortest form when there is no
default namespace and the *| prefix is used.
Selectors § 6.1.1 says:
Element type selectors that have no namespace component (no namespace
separator) represent elements without regard to the element's namespace
(equivalent to "*|") unless a default namespace has been declared for
namespaced selectors (e.g. in CSS, in the style sheet). If a default
namespace has been declared, such selectors will represent only elements
in the default namespace.
Then if there is no default namespace, *| (which we write as
QNamePrefix::ExplicitAnyNamespace) is equivalent to what we write as
QNamePrefix::ImplicitAnyNamespace; the latter has a shorter
serialization, so we should use that.
Properly set origin of fetch requests
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These changes aim to fix#15247
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- [x] These changes do not require tests because cors is already tested with different origins
These changes require changes in tests, but I need help with that (see comments below).
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Suppress CSS parser errors for vendor-prefixed properties.
This matches the behaviour of Gecko's CSS parser.
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- [X] There are tests for these changes
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In the next patch, we'll move logic to identify the children for traversal into
preprocess_children (which will be renamed), and the set_dirty_descendants logic
will move along with it. So left as-is, the code here will clobber the flags.
MozReview-Commit-ID: 7ZskKWD4QC3
rustify if statements style
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Rewrite if statement in more rusty style.
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This allows us to have ensure_data() and clear_data() functions on the TElement
trait, instead of hacking around it adding methods in random traits.
This also allows us to do some further cleanup, which I'd rather do in a
followup.
