Updating trunk VERSION from 4258.0 to 4259.0

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

Change-Id: I9b5e9e86da91c2b9cc908b27b38bad7841b26da8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2397316Reviewed-by: Chrome Release Bot (LUCI) <chrome-official-brancher@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#804831}

chrome/VERSION

 MAJOR=87
 MINOR=0
-BUILD=4258
+BUILD=4259
 PATCH=0