Fix more failing tests on Metal.

Everything appears to be working other than DDLOperatorEqTest, still
need to implement full mipmap support.

Bug: skia:8243
Change-Id: Ifb9e1abc850c9e6b01871a61c7bbbc5b23008037
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/201981
Commit-Queue: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
8 files changed