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

Fail: window.navigator.registerProtocolHandler is not defined.
Fail: Invalid protocol "http" allowed.
Fail: Invalid protocol "https" allowed.
Fail: Invalid protocol "file" allowed.
Fail: Invalid url "" allowed.
Fail: Invalid url "%S" allowed.
Fail: Invalid call did not succeed.