[PA] Don't DCHECK in IsManagedBy(NormalBcukets|DirectMap) on unallocated regions

All callers except one DCHECK the result, so returning false is
equivalent. Adding IsManagedByNormalBucketsOrDirectMap for the single
caller that doesn't DCHECK.

Change-Id: Ief57c509b32003404007a0c89931cd0587356c39
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3011302


Commit-Queue: Bartek Nowierski <bartekn@chromium.org>
Commit-Queue: Anton Bikineev <bikineev@chromium.org>
Auto-Submit: Bartek Nowierski <bartekn@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Cr-Commit-Position: refs/heads/master@{#899143}