Reduce binary size for client-only tor

Uncompressed, the Tor executable and associated libs as bundled in Tor Browser is 7.7 MB. If we want other browsers to adopt Tor, it would be good to make it a lot smaller if possible. What is responsible for the bulk? Can we cut out unused code from libcrypto and other libraries? Or can we reuse some shared libraries from the browser? Would it help to chop out unused code that implements relays, hidden services, etc.?