The patch I have in bug 1550034 will address this by disabling the test on !RELEASE_OR_BETA builds. Bug 1532596 covers the way to make the platform piece that the test depends on work on beta builds.
Bug 1550769 Comment 5 Edit History
Note: The actual edited comment in the bug view page will always show the original commenter’s name and original timestamp.
The patch I have in bug 1550034 will address this by disabling the test on RELEASE_OR_BETA builds. Bug 1532596 covers the way to make the platform piece that the test depends on work on beta builds.