GetProcessForPID usage was introduced here:
https://codereview.chromium.org/2390953003/

This was done for the App Launcher in
https://chromium.googlesource.com/chromium/src/+/80da61e18ab0c93c7fd5d9816979e155db8c3dbe

Given that the App Launcher is gone and that App support is slated for removal from Chrome https://blog.chromium.org/2016/08/from-chrome-apps-to-web.html, do we still need this?

Removing GetProcessForPID might be straightforward, but you're right there is a bigger question. app_mode actually started long ago for  Issue 13148 , for hosted apps. It's since been used for packaged apps, the app launcher, then bookmark apps (Issue 517682). "Bookmark apps" are still part of the progressive web app ecosystem. They've launched on all other platforms, but they haven't launched properly on Mac. Largely because of being held up by  Issue 308382  and the various bugs that feed into it. There _might_ be a resolution for that using Mus, but that's unlikely to involve any of the app_mode code.

So if bookmark apps never launch using app_mode on Mac, then this is probably code that can be purged with the rest of "apps". If we want to get bookmark apps out of limbo before Mus is ready on Mac, we may still want it.

Please note that https://codereview.chromium.org/2390953003/ has not landed yet. I filed a bug so I could add TODO to the code.

The CL mentioned has landed. Is this done?

Not yet, this is in progress. Thanks for letting me know

Erik had a strategy for passing the NSAppleEventDescriptor in/out via the OpenApplicationWithPath() call which I thought was pretty neat - https://codereview.chromium.org/2398853002/

Thanks! I'll look into it

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/18e4d08f3ea5d85cce6676cd4dc6e893b7d7824c

commit 18e4d08f3ea5d85cce6676cd4dc6e893b7d7824c
Author: spqchan <spqchan@chromium.org>
Date: Mon Oct 31 16:43:06 2016

Prepare chrome_main_app_mode_mac.mm for 10.9
- Remove GetProcessForPID()
- Ping with the bundle identifier instead of the psn

BUG= 652563 

Review-Url: https://codereview.chromium.org/2416313002
Cr-Commit-Position: refs/heads/master@{#428741}

[modify] https://crrev.com/18e4d08f3ea5d85cce6676cd4dc6e893b7d7824c/chrome/app_shim/chrome_main_app_mode_mac.mm