40d9e6729a
Refactor the test to use a python program to check that the background was successfully changed and re-enable the test on macOS. For running in automation, this test is dependent on Mac test runner instances being configured to allow users to change the desktop background. A code change to allow this has already been landed. See bug for the additional patches. Differential Revision: https://phabricator.services.mozilla.com/D72456