Fix: https://codereview.chromium.org/2614763002/

Requesting merge in M56 since:
1. this is a small local patch
2. Is Finch controlled
3. Finch experiment is not enabled in Stable (yet).
4. Will cause DCHECKs to fail in DEBUG mode.

The CL is ready for merge, if approved: https://codereview.chromium.org/2625933007/

Your change meets the bar and is auto-approved for M56. Please go ahead and merge the CL manually. Please contact milestone owner if you have questions.
Owners: amineer@(clank), cmasso@(bling), gkihumba@(cros), bustamante@(desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e3ddcd882959d97b711ebb4c705de8c568acb7ce

commit e3ddcd882959d97b711ebb4c705de8c568acb7ce
Author: vakh <vakh@chromium.org>
Date: Fri Jan 13 03:18:36 2017

[M56] DCHECK that full hash must be 32 bytes or 21 bytes long

Merges http://crrev.com/2614763002 to M56.

NOTRY=true
NOPRESUBMIT=true

BUG= 680346 

Review-Url: https://codereview.chromium.org/2625933007
Cr-Commit-Position: refs/branch-heads/2924@{#756}
Cr-Branched-From: 3a87aecc31cd1ffe751dd72c04e5a96a1fc8108a-refs/heads/master@{#433059}

[modify] https://crrev.com/e3ddcd882959d97b711ebb4c705de8c568acb7ce/components/safe_browsing_db/v4_store.cc
[modify] https://crrev.com/e3ddcd882959d97b711ebb4c705de8c568acb7ce/components/safe_browsing_db/v4_store.h
[modify] https://crrev.com/e3ddcd882959d97b711ebb4c705de8c568acb7ce/components/safe_browsing_db/v4_store_unittest.cc