header cleanup

Change-Id: I9d93add4e7998d8a1aa37cba9e7829fcbda867d5
Reviewed-on: https://skia-review.googlesource.com/15318
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>
9 files changed