Revert "ok, exit() child processes instead of _exit()"

This reverts commit 9ac801c12c48b67b48e5a8ef2876a093b7de73fc.

Reason for revert: breaks threaded mode.

Original change's description:
> ok, exit() child processes instead of _exit()
> 
> We want the atexit() hook to print deferred logs (crash dumps, etc.) only when the main, parent process exits.  Ending the child processes with _exit() instead of exit() avoids calling atexit() hooks, but also global destructors.  This is more complex than we need: we can just print before main() exits.  Only the main, parent process gets there.
> 
> This now runs each child process' global destructors, which makes trace.json "work": we get a trace of whichever child process finishes last.  It's a start.
> 
> Change-Id: I0cc2b12592f0f79e73a43a160b9fd06dba1fee25
> Reviewed-on: https://skia-review.googlesource.com/26800
> Commit-Queue: Mike Klein <mtklein@chromium.org>
> Reviewed-by: Brian Osman <brianosman@google.com>

TBR=mtklein@chromium.org,brianosman@google.com

Change-Id: I695dddaab3b5a51e4698bb7222fc723b544a1d64
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/26943
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
1 file changed