Fix new clang warning around shadowing.

clang now warns about method parameter names shadowing field names.

Change-Id: Ic67bd6d84fa515fb5342f284320130104f2ee292
Reviewed-on: https://skia-review.googlesource.com/c/173646
Auto-Submit: Ben Wagner <bungeman@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>
Reviewed-by: Hal Canary <halcanary@google.com>
1 file changed