These actually always return a value, despite the `CSSStyleSheet*`
return type. So, make that clearer by returning `GC::Ref<CSSStyleSheet>`
instead. This also means we can remove some ad-hoc error-checking code.
The spec is unclear about when exactly we should parse the style sheet.
Previously we'd do so before calling this algorithm, which was
error-prone, as seen by the bug fixed by the previous commit. The spec
for step 1 of "create a CSS style sheet" says:
1. Create a new CSS style sheet object and set its properties as
specified.
The definitions linked are UA-defined enough that it seems reasonable to
put the parsing here. That simplifies the user code a little and makes
it harder to mess up. It does raise the question of what to do if
parsing fails. I've matched our previous behaviour by just logging and
returning in that case.
While I'm modifying this method, I've also converted the bool params to
enums so they're a little clearer to read.
To prepare for introducing a CSS::URL type, we need to qualify any use
of LibURL as `::URL::foo` instead of `URL::foo` so the compiler doesn't
get confused.
Many of these uses will be replaced, but I don't want to mix this in
with what will likely already be a large change.
Resulting in a massive rename across almost everywhere! Alongside the
namespace change, we now have the following names:
* JS::NonnullGCPtr -> GC::Ref
* JS::GCPtr -> GC::Ptr
* JS::HeapFunction -> GC::Function
* JS::CellImpl -> GC::Cell
* JS::Handle -> GC::Root
LibWeb keeps growing and the Web namespace is filling up fast.
Let's put DOM stuff into Web::DOM, just like we already started doing
with SVG stuff in Web::SVG.
Until now we would simply apply stylesheets in the order they finished
loading. This patch adds a StyleSheetList object that hangs off of each
Document and contains all the style sheets in document order.
There's still a lot of work to do for a proper cascade, but at least
this makes us consistently wrong every time. :^)
