My guess is that it's not using IPC on OS level, like D-Bus on Linux, but rather a supervisior process starts and orchestrates child processes as needed. And all these processes use a shared memory model.

Here's the CEF docs on processes: https://chromiumembedded.github.io/cef/general_usage.html#pr...

EDIT: ...and the CEF docs on IPC: https://chromiumembedded.github.io/cef/general_usage.html#in...