[Devil] Dismiss errors in GetRecursiveDiskUsage
[Devil] Dismiss errors in GetRecursiveDiskUsage

When trying to compute the disk usage in bytes of a path, some files or
directories in it might be removed. Dismiss errors that such removals
would cause and log a warning instead.

TBR=jbudorick@chromium.org
Bug: chromium:807235
Change-Id: Ibb2eb7d827df0959a815e3aa1d5124cc50a6f4d2
Reviewed-on: https://chromium-review.googlesource.com/895482
Reviewed-by: Juan Antonio Navarro Pérez <1649bb5e6b9eafe026580e338065dc64ba6b80b2@chromium.org>
Commit-Queue: Juan Antonio Navarro Pérez <1649bb5e6b9eafe026580e338065dc64ba6b80b2@chromium.org>

catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult