[Tracing Clock Sync] Implement clock sync in Chrome

This CL implements tracing clock sync in Chrome.
PowerTracingAgent is the first example.

Design doc: https://goo.gl/8Vy6qX

BUG=542390

Review URL: https://codereview.chromium.org/1526883005

Cr-Commit-Position: refs/heads/master@{#366429}


CrOS-Libchrome-Original-Commit: 556e3a531d1fccf63a46fb74971e4d6ad65fc4be
2 files changed
tree: 1fa692e33e1acf6dbefd5cffaff62934b53efdc3
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/