Some layouts like table need some style overrides. We were handling this
in `ComputedValuesExt`, but it was messy, unreliable and too limited.
For example, we were assuming that a style with `display: table` would
belong to a table wrapper box or table grid box. However, certain HTML
elements can ignore their `display` value and generate a different kind
of box. I think we aren't doing that yet, but we will need this.
Also, resolving the used border of a table needs layout information,
which we don't have in `ComputedValuesExt`. This patch will allow to
improve border collapsing in a follow-up.
Signed-off-by: Oriol Brufau <obrufau@igalia.com>
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