This test makes sure that navigator.unregisterProtocolHandler throws the proper exceptions and has no-op default implementation.

Fail: window.navigator.unregisterProtocolHandler is not defined.
Fail: Invalid protocol "http" allowed.
Fail: Invalid protocol "https" allowed.
Fail: Invalid protocol "file" allowed.
Fail: Invalid protocol "web+" allowed.
Fail: Valid protocol "bitcoin" failed.
Fail: Valid protocol "geo" failed.
Fail: Valid protocol "im" failed.
Fail: Valid protocol "irc" failed.
Fail: Valid protocol "ircs" failed.
Fail: Valid protocol "magnet" failed.
Fail: Valid protocol "mailto" failed.
Fail: Valid protocol "mms" failed.
Fail: Valid protocol "news" failed.
Fail: Valid protocol "nntp" failed.
Fail: Valid protocol "sip" failed.
Fail: Valid protocol "sms" failed.
Fail: Valid protocol "smsto" failed.
Fail: Valid protocol "ssh" failed.
Fail: Valid protocol "tel" failed.
Fail: Valid protocol "urn" failed.
Fail: Valid protocol "webcal" failed.
Fail: Valid protocol "wtai" failed.
Fail: Valid protocol "xmpp" failed.
Fail: Invalid url "" allowed.
Fail: Invalid url "%S" allowed.
Fail: Invalid call did not succeed.