Fix DDLOperatorEqTest on Dawn backend.

If the backend doesn't support mipmaps, skip the test cases which
only differ by the mips flag.

Bug: skia:10361
Change-Id: I05e3bc59c2d9d1af6b5cb3659a7a346f2cdc8b82
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/299558
Commit-Queue: Stephen White <senorblanco@chromium.org>
Commit-Queue: Stephen White <senorblanco@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
1 file changed