GitLab

 Add launcher.launchFileManager()
  - move this part out of file_manager.js changes in CL:2500642
 Add ready() handler to read load time data
  - move this part out of file_manager.js changes in CL:2500642
 Add getVolumeManager() helper
  - to match this new helper, which was added in CL:2534551 for
    moving VolumeManager into JS modules
 Re-position the various background fake classes
  - move them so they are adjacent in the code

Tbr: alex
Bug: 1113981
Change-Id: Ia301098b5e0a357d69b7ee5e89560f7cc6b8210f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2539255Reviewed-by: Noel Gordon <noel@chromium.org>
Commit-Queue: Noel Gordon <noel@chromium.org>
Auto-Submit: Noel Gordon <noel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#827657}