Add perf benchmarks and more unit tests for matrix inversion

R=jvanverth@google.com, reed@google.com

Author: shawnsingh@chromium.org

Review URL: https://chromiumcodereview.appspot.com/22886010

git-svn-id: http://skia.googlecode.com/svn/trunk@10836 2bbb7eff-a529-9590-31e7-b0007b416f81
2 files changed