This can be simplified with termsql.
ps -C chromium-browser -o pmem | termsql -1 "SELECT SUM([%MEM]) FROM tbl"
Note, that currently it's not upload toNote, that currently it's not upload to PyPI, and also can only be installed system-wide (setup.py is a little broken), like sudo pip install https://github.com/tobimensch/termsql/archive/master.zip.
termsql is PyPIavailable on PyPI, and also can only be installed system-wide (setup.py is a little broken), likee.g. with sudo pippipx install https://github.com/tobimensch/termsql/archive/master.zip.