Revert "Migrate history_report to TaskScheduler API"
This reverts commit 2ee207f8e168f76deb5855f119816bbcbf2fe480.
Reason for revert: Caused Icing crashes. https://crbug.com/747849
Original change's description:
> Migrate history_report to TaskScheduler API
>
> GetBlockingPool() is replaced by SequencedTaskRunner. There's no
> per-task trait in SequencedTaskRunner, so the shutdown behavior are
> all set to BLOCK_SHUTDOWN.
>
> Bug: 667892
> Change-Id: I6e8f2507b201a8cb077d7338f504684ca1e232c8
> Reviewed-on: https://chromium-review.googlesource.com/580620
> Reviewed-by: Tommy Nyquist <nyquist@chromium.org>
> Commit-Queue: Tommy Nyquist <nyquist@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#488836}
TBR=nyquist@chromium.org,wychen@chromium.org
# Not skipping CQ checks because original CL landed > 1 day ago.
No-Presubmit: true
Bug: 667892
Change-Id: Id6dcee0dd905a6322f2ee2d46a5072d0f6e7bed7
Reviewed-on: https://chromium-review.googlesource.com/583907
Commit-Queue: John Budorick <jbudorick@chromium.org>
Reviewed-by: Tommy Nyquist <nyquist@chromium.org>
Reviewed-by: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#489132}4 files changed
