Updating trunk VERSION from 3871.0 to 3872.0

# This is an automated release commit.
# Do not revert without consulting chrome-pmo@google.com.
NOAUTOREVERT=true
TBR=cmasso@chromium.org

Change-Id: I6fe0d6e37e34a483082da5a7950c21a60178a10a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1730550Reviewed-by: Chrome Release Bot (LUCI) <chrome-official-brancher@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#683053}

chrome/VERSION

 MAJOR=78
 MINOR=0
-BUILD=3871
+BUILD=3872
 PATCH=0