This change fixes accessible-name computation for:
- an element that has empty text content but that also has a title
attribute (“tooltip”) with a non-empty value
- an img element whose alt attribute is the empty string but that also
has a “title” attribute with a non-empty value
Otherwise, without this change, the accessible name unexpectedly isn’t
computed correctly for those cases.
This change implements the “is a descendant of a native host language
text alternative element” condition in the “F: Name From Content” step
at https://w3c.github.io/accname/#step2F in the “Accessible Name and
Description Computation” spec — to ensure that all descendant nodes get
included as expected in computations for accessible names for elements.
Otherwise, without this change, Ladybird unexpectedly skips descendant
element nodes when computing accessible names — which can result in the
wrong accessible name being returned.
This change imports the WPT accname/name/comp_embedded_control.html
test, along with related resources files it depends on.
Note that in the wai-aria/scripts/aria-utils.js file, this changes the
get_computed_label call to use our window.internals.getComputedLabel.
