Remove GetBlockingPool() in wallpaper_manager.cc file.

The blocking pool has been deprecated in favor of TaskScheduler.

Bug: 667892
Change-Id: Iabaa23abc14ade5b5c0e4ed9bee6b8f574d7b689
Reviewed-on: https://chromium-review.googlesource.com/571306
Reviewed-by: Achuith Bhandarkar <achuith@chromium.org>
Commit-Queue: Xiaoqian Dai <xdai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#486943}
2 files changed