The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/98e3cb92c9dee46a3930327587d41aa954edccaa

commit 98e3cb92c9dee46a3930327587d41aa954edccaa
Author: Kim Paulhamus <kpaulhamus@chromium.org>
Date: Tue May 01 16:49:42 2018

Expose AES-GCM in the crypto library.

This will initially be used by cloud-assisted BLE, a protocol used by
the WebAuthN API to communicate with certain BLE devices without
explicit pairing.

Bug:  838568 
Change-Id: I4aa08787e677c3cc0b74c2e818126ada05bdba54
Reviewed-on: https://chromium-review.googlesource.com/1037206
Commit-Queue: Kim Paulhamus <kpaulhamus@chromium.org>
Reviewed-by: Adam Langley <agl@chromium.org>
Cr-Commit-Position: refs/heads/master@{#555071}
[modify] https://crrev.com/98e3cb92c9dee46a3930327587d41aa954edccaa/crypto/aead.cc
[modify] https://crrev.com/98e3cb92c9dee46a3930327587d41aa954edccaa/crypto/aead.h
[modify] https://crrev.com/98e3cb92c9dee46a3930327587d41aa954edccaa/crypto/aead_unittest.cc