Add various missing header files to BUILD.gn.

Change-Id: I6f4409e9e8c6d4a6d71bc41e57dce7417d7788f3
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/302440
Commit-Queue: John Stiles <johnstiles@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
1 file changed