Updating trunk VERSION from 3455.0 to 3456.0

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

Change-Id: I0918368073e853d13f7eca7870fbd59f7d6aee31
Reviewed-on: https://chromium-review.googlesource.com/1095331Reviewed-by: chrome-release-bot@chromium.org <chrome-release-bot@chromium.org>
Cr-Commit-Position: refs/heads/master@{#566027}

chrome/VERSION

 MAJOR=69
 MINOR=0
-BUILD=3455
+BUILD=3456
 PATCH=0