IWYU for some more test files starting with 'C'.

Change-Id: I010527b342cbfa0b425ef0d00966219413d9e77d
Reviewed-on: https://skia-review.googlesource.com/121886
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
9 files changed