request SPIR-V InputAttachment capability when needed

Bug: skia:
Change-Id: I800b2aaf250b39f7d5d5bf8d6c8f72afab0f3743
Reviewed-on: https://skia-review.googlesource.com/93720
Reviewed-by: Chris Dalton <csmartdalton@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
1 file changed