WR multi-document update
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The PR updates WR version to support multiple documents (https://github.com/servo/webrender/pull/1509) but doesn't take advantage of this new feature yet.
It also makes Servo to use `DevicePixel` from WR instead of rolling out another one.
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The alias is left there temporarilly and will be removed completely in a later commit where
also components/style/gecko/generated/structs_{debug|release}.rs are re-generated (they still
use the old alias).
Suppress CSS parser errors for vendor-prefixed properties.
This matches the behaviour of Gecko's CSS parser.
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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.
Removed unused import
Removed unused import `script_layout_interface::reporter::CSSErrorReporter in components/layout_thread/lib.rs
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Parallel layout optimizations
This takes some of the optimizations made to parallel styling in #16971 and applies them to parallel layout. Specifically:
* Reduce the chunk size, to increase chances for parallelism on trees with small fan-out.
* Reduce allocations by using SmallVec.
* Reduce task switching by processing up to one chunk of children within the same rayon task as the parent.
This cuts the "Primary Layout Pass" time in **half** on the MySpace page from [tp5n], and on my other real-world test pages it is a small improvement or close to no change.
[tp5n]: https://wiki.mozilla.org/Buildbot/Talos/Tests#tp5n_pages_set
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This commit splits the style and layout data in two separate refcells.
These transmutes have been a source of trouble (for example on Android), and
they feel like a hack anyway.
Fixes#16982
Stylist accessors
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Add accessor methods for the `device` and `ruleset` fields in the `Stylist` struct.
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Renamed constellation::Frame to constellation::BrowsingContext
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Now that script has `WindowProxy` rather than `BrowsingContext` objects, we can rename `Frame` in the constellation to `BrowsingContext`. In particular, this means that `FrameId`s are now `BrowsingContextid`s, which better captures their purpose (and they are used in a lot of places, not just the constellation).
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Scroll roots are no longer nested containers holding items, so instead
we need to track the offsets of each, carefully handling fixed position
items and stacking contexts that create new reference frames.
Additionally, we remove the complexity of the pre-computed page scroll
offset, instead opting to send script scrolls to the layout task in
order to more quickly have a ScrollState there that matches the
script's idea of the scroll world.
Fixes#16405.
This avoids the need for multiple layout RPC operations immediately
following return of control to script. This means that layout and
script can continue to operate in parallel at this point, rather
than one potentially waiting on the shared mutex to be unlocked.
This ensures that we can pass a node address as part of the asynchronous
transition end notification, making it safe to fire the corresponding
DOM event on the node from the script thread. Without explicitly rooting
this node when the transition starts, we risk the node being GCed before
the transition is complete.
This slims down SharedStyleContext, in preparation for a few things.
First, I would like to eventually move the stylist to the document in Servo, in
order for it to hold the StyleSheetSet.
Also, this gets rid of a fair amount of overhead while creating it in stylo.
Fixes bug 1363245.
I've chosen this approach mainly because there's no other good way to guarantee
the model is correct than holding the snapshots alive until a style refresh.
What I tried before this (storing them in a sort of "immutable element data") is
a pain, since we call into style from the frame constructor and other content
notifications, which makes keeping track of which snapshots should be cleared an
which shouldn't an insane task.
Ideally we'd have a single entry-point for style, but that's not the case right
now, and changing that requires pretty non-trivial changes to the frame
constructor.
MozReview-Commit-ID: FF1KWZv2iBM
Signed-off-by: Emilio Cobos Álvarez <emilio@crisal.io>