Updating trunk VERSION from 4459.0 to 4460.0

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

Change-Id: Icd85ae76a96a937958476707f372eb6fe4ac29fc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2787577
Bot-Commit: Chrome Release Bot (LUCI) <chrome-official-brancher@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#866903}

chrome/VERSION

@@ -1,4 +1,4 @@
 MAJOR=91
 MINOR=0
-BUILD=4459
+BUILD=4460
 PATCH=0