Revert "Barcode detection: split mojo interface into BarcodeDetection and Provider"

This reverts commit bb470a5.

Reason for revert: Caused compile failure (see
https://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Builder%20%28dbg%29/builds/90023)

Original change's description:
> Barcode detection: split mojo interface into BarcodeDetection and Provider
> 
> This CL splits the current shape_detection::mojom::BarcodeDetection
> into a BarcodeDetection proper and a BarcodeDetectionProvider (following
> a pattern similar to shape_detection::mojom::FaceDetection and
> FaceDetectionProvider). This division is reflected in the Mac and Android
> implementations.
> 
> The splitting is needed to add enumeration of the supported formats 
> (pre construction) and constructor options.  Wiring those in idl will
> happen in a subsequent CL, to limit the review cycles.
> 
> This CL also adds the necessary data types enum BarcodeFormat and 
> struct BarcodeDetectorOptions, which mimic the ones introduced
> in the WICG spec update that originated the issue tracker.
> 
> Layouttests (and the mock js service) and unittests updated.
> 
> 
> Bug: 747199
> Change-Id: Ib2ffa361465c50999f9c74537d9d7988fa30cd05
> Cq-Include-Trybots: master.tryserver.chromium.linux:linux_site_isolation;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel
> Reviewed-on: https://chromium-review.googlesource.com/582266
> Reviewed-by: Reilly Grant <reillyg@chromium.org>
> Reviewed-by: Avi Drissman <avi@chromium.org>
> Reviewed-by: Tom Sepez <tsepez@chromium.org>
> Commit-Queue: Miguel Casas <mcasas@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#490210}

TBR=avi@chromium.org,reillyg@chromium.org,mcasas@chromium.org,tsepez@chromium.org

Change-Id: Ia9654aa07034fc2f03d2b84fc176ba36700c1b99
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 747199
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_site_isolation;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel
Reviewed-on: https://chromium-review.googlesource.com/590869
Reviewed-by: meade_UTC10 <meade@chromium.org>
Commit-Queue: meade_UTC10 <meade@chromium.org>
Cr-Commit-Position: refs/heads/master@{#490226}

Author: wilddamon