Revert "Add the ability to pass use flags through cbuildbot to build_packages."

This reverts commit edbd709951ab9a56876cf75f10297df2180539b3.

BUG=soon
TEST=none

Review URL: http://codereview.chromium.org/6794043

Change-Id: Iff1e1157f1291e091b205e1c1aac280d760bd95e
2 files changed