Updating trunk VERSION from 4248.0 to 4249.0

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

Change-Id: I93ca2df444e6277bfe02c22ac19666f0a137896b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2383231Reviewed-by: Chrome Release Bot (LUCI) <chrome-official-brancher@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#802856}

chrome/VERSION

 MAJOR=87
 MINOR=0
-BUILD=4248
+BUILD=4249
 PATCH=0