Updating trunk VERSION from 3780.0 to 3781.0

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

Change-Id: I0f0f198e369281f20d52dd9241a225a07d982197
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1587173
Reviewed-by: chrome-release-bot@chromium.org <chrome-release-bot@chromium.org>
Cr-Commit-Position: refs/heads/master@{#654781}