Updating trunk VERSION from 3878.0 to 3879.0

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

Change-Id: I01039a3f783214c4b6457109b0671d33d0acf383
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1745435Reviewed-by: Chrome Release Bot (LUCI) <chrome-official-brancher@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#685448}

chrome/VERSION

 MAJOR=78
 MINOR=0
-BUILD=3878
+BUILD=3879
 PATCH=0