This test makes sure that a canvas with and without fallback content each has the right role and description.
On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
PASS axContainer.childrenCount is 2
Canvas 1 description: Canvas label
Canvas 1 role: AXRole: AXCanvasWithFallbackContent
Canvas 2 description:
Canvas 2 role: AXRole: AXCanvasWithFallbackContent
PASS successfullyParsed is true
TEST COMPLETE