add apply method to drawlooper

Bug: skia: 4783

Change-Id: I3eabe364c9b377d1f0c024131f8cbdabc094fa8e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/228574
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
Auto-Submit: Mike Reed <reed@google.com>
3 files changed