Create a skeleton App Service and App Registry.

This CL creates the App Service as a in-process per-profile service, and
attaches the App Registry to it.

App Service is currently located in chrome/browser as many of its direct
dependencies (which are not yet connected to the service) live there.
Over time, we will refactor the dependencies such that:

1. data which can be made independent of chrome/browser is moved within
   the App Service
2. components which rely on that data access it asynchronously via the
   App Service

This will allow us to move the App Service to chrome/services in the
future.

BUG=826982

Change-Id: Ia7608fbb8c8b235d2b3e69ffa447963b32f2d5f0
Reviewed-on: https://chromium-review.googlesource.com/1127513
Commit-Queue: Dominick Ng <dominickn@chromium.org>
Reviewed-by: Bernhard Bauer <bauerb@chromium.org>
Reviewed-by: Sam McNally <sammc@chromium.org>
Reviewed-by: Trent Apted <tapted@chromium.org>
Reviewed-by: Ken Rockot <rockot@chromium.org>
Cr-Commit-Position: refs/heads/master@{#575968}
20 files changed