Let the clang perf waterfall use its dedicated rel builder slave.
Let the clang perf waterfall use its dedicated rel builder slave.

TBR=bevc
Review URL: http://codereview.chromium.org/6966034

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@86438 0039d316-1c4b-4281-b951-d872f2087c98

eunchong/build,eunchong/build,eunchong/build,eunchong/build