For the following, you need a recent nightly with Azure canvas pref'ed on and gfx.canvas.azure.backends = "cairo". On Windows, http://www.smashcat.org/av/canvas_test/ renders as a blank (white) rectangle. On Android (tested Nexus 7 (4.1) and HTC One X (4.0)), http://www.kevs3d.co.uk/dev/asteroids/index-debug.html renders very badly (see screenshot, coming soon). I've filed these as one bug for now, I suspect there might be a single cause, but we might want to split the bug later.
note on the attachment, I think the double awesome bar is a separate bug, due to my build (it doesn't seem to be present on the nightly build I downloaded).
The Windows bug only happens with Direct2D on, so it must be different from the Android bug, so going to split this off into a separate bug...
Split off bug 779650 for the Windows/smashcat bug
Seems to be a problem with the 9arg flavour of drawImage. I have no idea why it would only affect Android, and not affect the Thebes canvas
Created attachment 649189 [details] [diff] [review] patch
test coming soon...
test not coming soon after all. This bug is caught by the drawImage.9arg tests in test_canvas when run locally, I don't know why it doesn't fail on Try, but I can't imagine a test which would fail there is the test_canvas ones don't.
Created attachment 649490 [details] [diff] [review] patch was missing an include, carrying r=bas