build_packages: Add option to build all packages with goma

With some recent bugfixes in goma, we are able to run successfully run
build_packages using goma to build everything aside from the few packages
naturally blacklisted by goma. This CL is meant to provide an easy handle
to enable goma usage without disrupting the normal build process.

The option flag in this CL is distinct from the existing --run_goma option,
as that flag only ensures that goma is running for the Chrome build and
does not cause all packages to be built using goma.

BUG=None
TEST=`./build_packages --board=amd64-generic --build_all_with_goma`
TEST=`./build_packages --board=amd64-generic`

Change-Id: I90dc0e5bb927eb2975bc903799b006bbd6204f8a
Reviewed-on: https://chromium-review.googlesource.com/1437376
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Chris McDonald <cjmcdonald@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
1 file changed