Add StackBench to measure performance on stack-like (fixed element size) work loads.

BUG=303282
R=reed@google.com, caryclark@google.com, mtklein@chromium.org

Author: mtklein@google.com

Review URL: https://codereview.chromium.org/110893007

git-svn-id: http://skia.googlecode.com/svn/trunk@12940 2bbb7eff-a529-9590-31e7-b0007b416f81
2 files changed