The focus chain always consists of newly created GC::Root objects, so
the condition always produced `false`. The fix is to use GC::Root's
overloaded operator== method, which compares the pointers of the stored
type.
This fixes Figma dropdowns and context menus instantly disappearing
upon opening them. This is because they become focused when they insert
them. Because of this bug, it would fire blur events all the way up to
and including the window. Figma listens for the blur event on the
window, and when received, it will instantly hide dropdowns and context
menus. The intention behind this seems to be hiding them when the user
clicks off the browser window, or switches tab.
I believe this is an error in the UI Events spec, and it should be
updated to match the HTML spec (which uses WindowProxy everywhere).
This fixes a bunch of issues already covered by existing WPT tests.
Spec bug: https://github.com/w3c/uievents/issues/388
Note that WebKit has been using WindowProxy instead of Window in
UI Events IDL since 2018:
816158b4aa
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
