Fixing how got_revision is calculated for llvm watefall.
Fixing how got_revision is calculated for llvm watefall.

BUG=None
TEST=None
R=nsylvain@google.com

Review URL: http://codereview.chromium.org/10019023

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@131367 0039d316-1c4b-4281-b951-d872f2087c98

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