Updating trunk VERSION from 4392.0 to 4393.0

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

Change-Id: I048f5e4f712550b844aaa86567b0303a76273df4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2633359Reviewed-by: Chrome Release Bot (LUCI) <chrome-official-brancher@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#844432}

chrome/VERSION

 MAJOR=90
 MINOR=0
-BUILD=4392
+BUILD=4393
 PATCH=0