This will allow Servo to add custom types of damage in the near future
which correspond to minor phases layout. The damage exposed by Stylo
only corresponds to the major layout phses. In the future, both phases
will likely be managed by Servo itself and implementors will need to
provide their own damage system entirely.
Testing: This shouldn't change behavior and thus is covered by existing
tests.
Stylo PR: https://github.com/servo/stylo/pull/207
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
