Make sticky chromium revision available for perf tests.

This file will be regularly updated with the chromium revision to be used by performance test buildbots.

R=danno@chromium.org

Review URL: https://codereview.chromium.org/18244003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15442 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

tools/perf_tests/chromium_revision

+209619