Added check for blink's perf cfg file. The bisect/perf bots work by modifying a ...

Added check for blink's perf cfg file. The bisect/perf bots work by modifying a .cfg file with the parameters of the job (ie. revision, command, repetitions, etc...) and submitting that as a patch to the bot. Since a single patch can't span both blink and chromium, we need a run-perf-test.cfg in each depot that we're likely to try running perf tests from.

Waiting on: https://codereview.chromium.org/33553003/

BUG=
NOTRY=true

Review URL: https://codereview.chromium.org/34723005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230222 0039d316-1c4b-4281-b951-d872f2087c98