Adding support for playback to L32/S32/F16 canvas.

Playback of my test GM works correctly on both raster and GPU, in all three modes.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1893393002

Review URL: https://codereview.chromium.org/1893393002
6 files changed