fix size_t/int warnings

TBR=caryclark@google.com

Author: reed@chromium.org

Review URL: https://codereview.chromium.org/265163003

git-svn-id: http://skia.googlecode.com/svn/trunk/src@14560 2bbb7eff-a529-9590-31e7-b0007b416f81
3 files changed