Use a bench alert algorithm with wider ranges. TBR=jvanverth NOTRY=true

BUG=skia:2169
R=jvanverth@google.com, bsalomon@google.com, robertphillips@google.com
TBR=jvanverth@google.com

Author: bensong@google.com

Review URL: https://codereview.chromium.org/164553002

git-svn-id: http://skia.googlecode.com/svn/trunk@13440 2bbb7eff-a529-9590-31e7-b0007b416f81
6 files changed