Support of zygote-like process forking is done as:
* The b2g chrome process forks a child process that will be the template for forking other content processes.
* The template process starts running to some point and freeze.
* When ready, the chrome process starts requesting the template to fork content proceses.
* The content processes forked from the template process recovers its states including the threads, file descriptors for epoll, signaling and IPC.
Recovery of the process states are done by wrapping some system and pthread calls to record the states in the template process and recover in the forked content process.
