Updating trunk VERSION from 3160.0 to 3161.0

TBR=dimu@chromium.org

Change-Id: Ia2d09762cfbb4f4e3f56ac7d1340dd267e7abc0b
Reviewed-on: https://chromium-review.googlesource.com/575570Reviewed-by: chrome-release-bot@chromium.org <chrome-release-bot@chromium.org>
Cr-Commit-Position: refs/heads/master@{#487363}

chrome/VERSION

 MAJOR=61
 MINOR=0
-BUILD=3160
+BUILD=3161
 PATCH=0