Reland of ix misc asserts and checks found by fuzzer (patchset #1 id:1 of https:...

Reland of ix misc asserts and checks found by fuzzer (patchset #1 id:1 of https://codereview.chromium.org/1713413002/ )

Reason for revert:
deps instability seemingly fixed. trying again.

Original issue's description:
> Revert of fix misc asserts and checks found by fuzzer (patchset #1 id:1 of https://codereview.chromium.org/1713383002/ )
>
> Reason for revert:
> speculative deps-roll fix
>
> Original issue's description:
> > fix misc asserts and checks found by fuzzer
> >
> > BUG=skia:
> > GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1713383002
> >
> > TBR=robertphilips
> >
> > Committed: https://skia.googlesource.com/skia/+/00bea4ad310c4ec4dd95809b47ce3fbfa8fd0e1e
>
> TBR=robertphillips@google.com
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/d98ef6377269e3596423225ab922301ed40529a0

TBR=robertphillips@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1723473002