Class to exchange OAuth refresh token from host config.

This class accepts a refresh token read from the host config. It
returns either a new refresh token with updated scopes, or a status code
to indicate no upgrade is needed.

Bug: 954427
Change-Id: I806abe0b1ebe2a979640cde07b3eb15a14cbe3e8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1627693
Commit-Queue: Joe Downing <joedow@chromium.org>
Reviewed-by: Joe Downing <joedow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#662856}
3 files changed