Fix fragment processors and unit tests which mix ints and floats.

These need to change because type coercion in SkSL is about to become
more strict in a followup CL; we are disallowing expressions that mix
ints and floats without a cast.

Change-Id: Iff5e2820806b9419afdfcbf25d4a7f96f2eeeccb
Bug: skia:11164
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/353416
Commit-Queue: John Stiles <johnstiles@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
7 files changed