Remove requirement of chrome_rev for Chrome buildbot type.
Remove requirement of chrome_rev for Chrome buildbot type.

BUG=None
TEST=started master, ran chrome pfq.
TBR=scottz

Review URL: http://codereview.chromium.org/7511007

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@95388 0039d316-1c4b-4281-b951-d872f2087c98

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