ARIAProperties.json5 represents the certain rules captured in the ARIA spec.
This change also uses it to generate the list of ARIA attribute name constants,
and to generate the ARIA autocompletion configuration for devtools.
Also adds pyjson5 as a third_party library.
Change-Id: I622e590196be667ed97288a73d040856380f3bf9
Reviewed-on: https://chromium-review.googlesource.com/737397
Commit-Queue: Alice Boxhall <aboxhall@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Reviewed-by: Joel Einbinder <einbinder@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#560222}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: a39ce6e61cd170b5b549f119f3b6f7a08253cba9