I'm struggling with the same issue: how to stop fork() from being called in the java process (in single process / no sandbox mode). Experiencing the same random segfaults in libjvm.so as reported here.
I've tried blocking the actual call to fork() with an LD_PRELOAD, but then chrome logs the error "FATAL:zygote_host_impl_linux.cc(218)] Cannot communicate with zygote" and kills the parent process.
It looks like the entire zygote-related setup is just unnecessary. In single process mode, even if the zygote is created successfully, it won't be used for anything. My next step is to make a custom cef build that just disables the zygote.
Has anyone else made progress on this? For instance, by finding a way to support creating a zygote without using fork?