Moving OAuthToken AsyncTasks from SERIAL_EXECUTOR to SequencedTaskRunner

Bug: 877963
Change-Id: I9d6e3c0503d0a9726c6c94cf5186094bab712f07
Reviewed-on: https://chromium-review.googlesource.com/c/1456938
Commit-Queue: Yuwei Huang <yuweih@chromium.org>
Auto-Submit: Sam Maier <smaier@chromium.org>
Reviewed-by: Yuwei Huang <yuweih@chromium.org>
Cr-Commit-Position: refs/heads/master@{#631856}
2 files changed