Remove ViewsDelegate::GetBlockingPoolTaskRunner().

Consequentially cleaning up another use of deprecated GetBlockingPool().

R=sky@chromium.org

Bug: 667892
Change-Id: Iaf99f86311f9d14e6dcc25eab71d83026a59e9bf
Reviewed-on: https://chromium-review.googlesource.com/600507
Commit-Queue: Gabriel Charette <gab@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#492053}
10 files changed