Don't build recovery if we didn't build base.
Don't build recovery if we didn't build base.

Chrome PFQs brand officially but don't produce all the artifacts.

BUG=chromium-os:29829
TEST=try

Change-Id: I334a108e2a18f797c5f1e4d508ddb1a3cf92e2db
Reviewed-on: https://gerrit.chromium.org/gerrit/21280
Reviewed-by: David James <f231dc574bbeb62604660cbc162d1b8642a0a3af@chromium.org>
Tested-by: Peter Mayo <3d31fdaf44dc55bb1b4f50b19df9bc879177d37a@chromium.org>
Commit-Ready: Peter Mayo <3d31fdaf44dc55bb1b4f50b19df9bc879177d37a@chromium.org>

coreos/chromite,bpsinc-native/src_third_party_chromite,zhang0137/chromite,bpsinc-native/src_third_party_chromite,coreos/chromite,zhang0137/chromite,chadversary/chromiumos.chromite,chadversary/chromiumos.chromite,bpsinc-native/src_third_party_chromite,zhang0137/chromite,coreos/chromite