Updating trunk VERSION from 3423.0 to 3424.0

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

Change-Id: Ia33e986c7be678e90351a0a0dd6e08cd8903137a
Reviewed-on: https://chromium-review.googlesource.com/1046004Reviewed-by: chrome-release-bot@chromium.org <chrome-release-bot@chromium.org>
Cr-Commit-Position: refs/heads/master@{#556372}

chrome/VERSION

 MAJOR=68
 MINOR=0
-BUILD=3423
+BUILD=3424
 PATCH=0