Make sure directly-composited animated GIFs properly get suspended / resumed based on visibility inside viewport.

On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".


PASS isImageAnimated() became true
Scroll down so that the image is no longer visible
PASS isImageAnimated() became false
Animation was paused, scroll up so that the image is visible again
PASS isImageAnimated() became true
PASS internals.imageFrameIndex(testImage) became different from frameIndexImageWasPausedAt
PASS successfullyParsed is true

TEST COMPLETE