Adds ability for chrome to behave as mojo_runner

This adds the arg use_mash that is only true on chromeos. Once
compiled with use_mash if you supply --mash to chrome it'll start the
shell inside chrome.
I haven't wired chrome up to start in this environment. Will do that
next.

BUG=581539
TEST=none
R=ben@chromium.org

Review URL: https://codereview.chromium.org/1722743002

Cr-Commit-Position: refs/heads/master@{#377113}


CrOS-Libchrome-Original-Commit: d6439eceec0ac412e5ce440847609a4d807e0f90
15 files changed
tree: 2fb8a11bf7716f5d1b3618b84c228a3495623972
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/