Clean up a few IWYU issues

Spun off from the SkTFitsIn CL.

Change-Id: I686d680df6a36ebc02db3847ad5e2cedcbcd67ef
Reviewed-on: https://skia-review.googlesource.com/134083
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Klein <mtklein@chromium.org>
6 files changed