GitLab

Adding support for PrintBackend queries to happen out of the browser
process requires related data structures to be made available via a Mojo
interface.  These are moved into their own mojom file separate from the
common definition in printing/mojom since they are specific to a new
process being introduced and do not need to be encumbered by the
dependencies which exist for print.mojom.

Starting with the historically most prolific cause of browser crashes
from printing (GetPrinterSemanticCapsAndDefaults), work towards having
support definitions to enable that query to be moved out-of-process.

Add a mojo definition to go with the printing::AdvancedCapability which
is needed to support the larger query on ChromeOS.

Bug: 809738
Change-Id: I05bbc441873d6f3a88ae57a27c5abe6c7c4be47b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2387543
Commit-Queue: Alan Screen <awscreen@chromium.org>
Reviewed-by: Will Harris <wfh@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Daniel Hosseinian <dhoss@chromium.org>
Cr-Commit-Position: refs/heads/master@{#812993}