Implement device token fetcher

First step in mechanism for fetching cloud-based policy for CrOS.

BUG=none
TEST=DeviceTokenFetcher*

Review URL: http://codereview.chromium.org/4121003

git-svn-id: http://src.chromium.org/svn/trunk/src/chrome/browser/policy/proto@64388 4ff67af0-8c30-449e-8e8b-ad334ec8d88c
1 file changed
tree: 26366d9e7539d04b7645422f3e9f5cfb416d3f7e
  1. device_management_backend.proto