Barcode detection: add |format| to DetectedBarcode

this CL adds |format| to the DetectedBarcode idl to catch up with
the Spec [1]; it also wires filling it in from the Mac and Android
implementations through the Mojo interface, and updates the
appropriate unit tests and/or expectations.

The enum BarcodeFormat is moved from a .mojom to another to
make it available to BarcodeDetectionResult.

[1] https://wicg.github.io/shape-detection-api/#detectedbarcode-section

Test: unit tests and web_tests
Bug: 938663
Change-Id: Ib802679274f3f99c3d5a53425a264fb598e4855d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1509364
Commit-Queue: Miguel Casas <mcasas@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Robert Sesek <rsesek@chromium.org>
Reviewed-by: Jao-ke Chin-Lee <jchinlee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#640779}
23 files changed