Google has invested massively into security. On various platforms (non-Chromium Linux excluded), Google Chrome uses advanced defence-in-depth that make Chrome much more secure than Firefox on the same machine. Their origin-based process separation make Chrome a memory hog but protect tab processes from each other in a way Firefox doesn't bother with just yet.
Chrome may be a privacy nightmare, but in terms of security it beats Mozilla.
Chrome may be a privacy nightmare, but in terms of security it beats Mozilla.