This is caused by the call to startAnimation added to CachedImage::didAddClient(). Before r214503 the gif animation never really started, so we always ended up drawing the first frame, but now the animation is started and the second frame is rendered (the red one). I have no idea why this doesn't fail in apple ports, though.
Test svg/animations/animated-svg-image-outside-viewport-paused.html also fails -PASS Basic video stats +FAIL Basic video stats promise_test: Unhandled rejection with value: object "TypeError: undefined is not an object (evaluating 'senderParameters.encodings[0].fec')"
Looks like this is fixed now, will attach a patch to remove the expected fail.
Created attachment 420436 [details] Patch
Comment on attachment 420436 [details] Patch For reference, this was fixed by r272776 (bug 221637).
Committed r272899: <https://commits.webkit.org/r272899> All reviewed patches have been landed. Closing bug and clearing flags on attachment 420436 [details].