Add --skip_cpu and --skip_gpu options to tests

BUG=skia:2074
R=djsollen@google.com, mtklein@google.com

Author: borenet@google.com

Review URL: https://codereview.chromium.org/144343004

git-svn-id: http://skia.googlecode.com/svn/trunk@13223 2bbb7eff-a529-9590-31e7-b0007b416f81
2 files changed