This is a testharness.js-based test.
Found 8 FAIL, 0 TIMEOUT, 0 NOTRUN.
[FAIL] DeviceChangeEvent interface: existence and properties of interface object
assert_own_property: self does not have own property "DeviceChangeEvent" expected property "DeviceChangeEvent" missing
[FAIL] DeviceChangeEvent interface object length
assert_own_property: self does not have own property "DeviceChangeEvent" expected property "DeviceChangeEvent" missing
[FAIL] DeviceChangeEvent interface object name
assert_own_property: self does not have own property "DeviceChangeEvent" expected property "DeviceChangeEvent" missing
[FAIL] DeviceChangeEvent interface: existence and properties of interface prototype object
assert_own_property: self does not have own property "DeviceChangeEvent" expected property "DeviceChangeEvent" missing
[FAIL] DeviceChangeEvent interface: existence and properties of interface prototype object's "constructor" property
assert_own_property: self does not have own property "DeviceChangeEvent" expected property "DeviceChangeEvent" missing
[FAIL] DeviceChangeEvent interface: existence and properties of interface prototype object's @@unscopables property
assert_own_property: self does not have own property "DeviceChangeEvent" expected property "DeviceChangeEvent" missing
[FAIL] DeviceChangeEvent interface: attribute devices
assert_own_property: self does not have own property "DeviceChangeEvent" expected property "DeviceChangeEvent" missing
[FAIL] DeviceChangeEvent interface: attribute userInsertedDevices
assert_own_property: self does not have own property "DeviceChangeEvent" expected property "DeviceChangeEvent" missing
Harness: the test ran to completion.