Updating trunk VERSION from 3508.0 to 3509.0

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

Change-Id: Ibfc1117d1c08fd3fd8a125a8dc2af9d159b4028b
Reviewed-on: https://chromium-review.googlesource.com/1156066Reviewed-by: chrome-release-bot@chromium.org <chrome-release-bot@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579298}

chrome/VERSION

 MAJOR=70
 MINOR=0
-BUILD=3508
+BUILD=3509
 PATCH=0