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.

Start with a mojo definition for the
printing::PrinterSemanticCapsAndDefaults::Paper structure, which is
required for the larger query.

Bug: 809738
Change-Id: Id7d52f131f8587b9edc50c8e1c4f8b6718998965
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2387409Reviewed-by: Robert Sesek <rsesek@chromium.org>
Reviewed-by: Ken Rockot <rockot@google.com>
Reviewed-by: Daniel Hosseinian <dhoss@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Alan Screen <awscreen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#812424}