Remove more headers from include/gpu

TBR=bsalomon@google.com

Change-Id: I93b28cfcb4d7b50c12e24ea81faab680bccce9ef
Reviewed-on: https://skia-review.googlesource.com/14036
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
9 files changed