Updating trunk VERSION from 4119.0 to 4120.0

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

Change-Id: Ic1e9a56fb5806a89ac56f0facf37b88c4cd7c361
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2155809Reviewed-by: Chrome Release Bot (LUCI) <chrome-official-brancher@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#760337}

chrome/VERSION

 MAJOR=84
 MINOR=0
-BUILD=4119
+BUILD=4120
 PATCH=0