MutationRecord should be exposed on window but not constructible

On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".


PASS window.MutationRecord is non-null.
PASS typeof MutationRecord is "object"
PASS new MutationRecord threw exception TypeError: MutationRecordConstructor is not a constructor (evaluating 'new MutationRecord').
PASS record instanceof MutationRecord is true
PASS successfullyParsed is true

TEST COMPLETE