Version 4.4.42.1 (cherry-pick)

Merged 4c1f9d53

Revert of deprecate non-phantom weak callbacks (patchset #1 id:1 of https://codereview.chromium.org/1103173002/)

TBR=dcarney@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1103273008

Cr-Commit-Position: refs/heads/4.4.42@{#2}
Cr-Branched-From: 29bee160-refs/heads/master@{#28117}