Upstream OmahaBase refactoring.

Group mLatestVersion and mMarketURL into VersionConfig to allow the flexibility
to return different version config in downstream.

Bug: b/77151591
Change-Id: Ie251a5f953a82a480ea19973b41fdeb8c687100e
Reviewed-on: https://chromium-review.googlesource.com/987836
Reviewed-by: Tommy Nyquist <nyquist@chromium.org>
Reviewed-by: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
Commit-Queue: Shuo Weng <shuow@google.com>
Cr-Commit-Position: refs/heads/master@{#549445}
3 files changed