move libevent into base

This simplifies the process of bootstrapping gn standalone.

And libevent is not really used outside of base. base is actually its only client.

BUG=569352
TEST=See CL for details for how to reproduce this.
R=thestig@chromium.org
TBR=cpu@chromium.org

Review URL: https://codereview.chromium.org/1531573008

Cr-Commit-Position: refs/heads/master@{#366282}


CrOS-Libchrome-Original-Commit: c7ebe6daa79da2e351345065020cc7f216126f15
3 files changed
tree: 81ba6f378986bfe5432b1cd95fda69bc52c73732
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/