Revert of fix casts (patchset #1 id:1 of https://codereview.chromium.org/979453004/)

Reason for revert:
64-bit windows build warnings-as-errors

Original issue's description:
> (starting with mtklein's 966503002 mod to 963593003)
> fix casts
>
> Committed: https://skia.googlesource.com/skia/+/9e73a84deb5e6c201081b1d30175863898543e8d

TBR=caryclark@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/977583007
1 file changed