fix some clangtidy warnings

unnecessary copies in for loop

Bug: skia:
Change-Id: I494daa2524f3cd75b934572a4ecd0ff4b18ac8a9
Reviewed-on: https://skia-review.googlesource.com/105741
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Mike Reed <reed@google.com>
1 file changed