Updating trunk VERSION from 4004.0 to 4005.0

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

Change-Id: I8dd630b30d06ca7eea351a388f4f58a5abab4d91
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1979061Reviewed-by: Chrome Release Bot (LUCI) <chrome-official-brancher@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#727071}

chrome/VERSION

 MAJOR=81
 MINOR=0
-BUILD=4004
+BUILD=4005
 PATCH=0