Add features flag to gmerge and some whitespace cleanup.

Change-Id: I95aec88a491b0aee08f100af72d608b326fcf9c4

BUG=chromium-os:13992
TEST=Ran sudo gmerge chromos-base/gmerge to update to latest gmerge and then
ran sudo gmerge --features=test chromeos-base/metrics and saw test phase
run on dev machine.

Review URL: http://codereview.chromium.org/6824021
2 files changed