Make GrTextureStripAtlas DDL friendly

Change-Id: If8fdd7a1c027bc2b2791cfe1af13f99c2561d93d
Reviewed-on: https://skia-review.googlesource.com/113268
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
7 files changed