GitLab

Restructure how shims connect to be as follows
* (the shim process connects and creates an AppShimHostBootstrap)
* OnShimProcessConnected is called with the bootstrap, and then split
  to two paths
  * OnShimProcessConnectedForLaunch if we should open a new window
    * (e.g, user clicked on the icon)
    * Use the AppShimRegistry to create a list of windows to open
    * Potentially-asynchronously load the profiles, and then
    * OnShimProcessConnectedForLaunch will go through those profiles
      and create new app windows for them
      * If the app shim is an "old" shim that specified a profile, then
        only open the specified profile
  * OnShimProcessConnectedForRegisterOnly if not
    * (e.g, Chrome created an app window on its own and we're starting
      the shim to display it in its own process)
    * Search for an existing AppShimHost to connect to
    * Create one if needed only because tests want this (that cleanup
      can come later)
* OnShimProcessConnectedAndAllLaunchesDone is then called by both of
  the above branches. This function will
  * If the above-branch found or created an AppShimHost, then connect
    the bootstrap to it
  * Otherwise, tell the bootstrap that it should quit.

The big difference in structure here is how we load profiles. Prior to
this change, we
- Had OnShimProcessConnected asynchronously load the list of profiles
  for which the app is installed
- Then selected one profile, send it to LoadProfileAndApp, and only
  attached the shim to that one profile.
By contrast, we now
- Read profiles from the AppShimRegistry
- Load all profiles we may want to launch via a chain of calls to
  LoadProfileAndApp

TBR=dominickn

Bug: 1001213
Change-Id: I4b4355cc79606fc33a6de926af00bce48c086100
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1928016Reviewed-by: ccameron <ccameron@chromium.org>
Commit-Queue: ccameron <ccameron@chromium.org>
Cr-Commit-Position: refs/heads/master@{#719201}