Re-enable 3 clang warnings

Bug: skia:7462
Change-Id: Iba0af2f0ff8ef646f93a0e2ced083d99020a38c9
Reviewed-on: https://skia-review.googlesource.com/90842
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
1 file changed