This is *extremely* common on the web, but barely shows up at all in
JavaScript benchmarks.
A typical example is setting Element.innerHTML on a HTMLDivElement.
HTMLDivElement doesn't have innerHTML, so it has to travel up the
prototype chain until it finds it.
Before this change, we didn't cache this at all, so we had to travel
the prototype chain every time a setter like this was used.
We now use the same mechanism we already had for GetBydId and cache
PutById setter accesses in the prototype chain as well.
1.74x speedup on MicroBench/setter-in-prototype-chain.js
Browsers such as Chrome and Firefox apply an arbitrary scale to the
current font size if `normal` is used for `line-height`. Firefox uses
1.2 while Chrome uses 1.15. Let's go with the latter for now, it's
relatively easy to change if we ever want to go back on that decision.
This also requires updating the expectations for a lot of layout tests.
The upside of this is that it's a bit easier to compare our layout
results to other browsers', especially Chrome.
I was investigating an optimization in this area, and while it
didn't seem to have a noticable improvement, it still seems
useful to apply this change.
ParsedFontFace and FontLoader now both keep track of which
CSSStyleSheet (if any) was the source of the font-face, so the URLs can
be completed correctly.
This is the simplest fix I could find that resolves a buggy interaction
between this and the CSS fetch algorithms, which also doesn't regress
anything. (As far as I can tell.)
Convert FontLoader to use fetch_a_style_resource(). ResourceLoader used
to keep its downloaded data around for us, but fetch doesn't, so we use
Gfx::Typeface::try_load_from_temporary_memory() so that the font has a
permanent copy of that data.
Typeface::try_load_from_externally_owned_memory() relies on that
external owner keeping the memory around. However, neither WOFF nor
WOFF2 do so - they both create separate ByteBuffers to hold the TTF
data. So, rename them to make it clearer that they don't have any
requirements on the byte owner.
Shared workers are essentially just workers that may be accessed from
scripts within the same origin. There are plenty of FIXMEs here (mostly
building on existing worker FIXMEs that are already in place), but this
lets us run the shared worker variants of WPT tests.
We currently have a single IPC to set clipboard data. We will also need
an IPC to retrieve that data from the UI. This defines system clipboard
data in LibWeb to handle this transfer, and adds the IPC to provide it.
The editing command that relies the most on this, `insertLinebreak`,
did not perform a layout update after inserting a `<br>` which caused
this algorithm to always return false. But instead of actually building
the layout tree needlessly, we can check the DOM tree instead.
