Updating trunk VERSION from 3255.0 to 3256.0

TBR=anantha@chromium.org

Change-Id: I83c579841ff5690a6bf6f9d14b97ed34b4159bd6
Reviewed-on: https://chromium-review.googlesource.com/748581Reviewed-by: chrome-release-bot@chromium.org <chrome-release-bot@chromium.org>
Cr-Commit-Position: refs/heads/master@{#513060}

chrome/VERSION

 MAJOR=64
 MINOR=0
-BUILD=3255
+BUILD=3256
 PATCH=0