Adds a "namespaces" option to the gadget definition, which takes a
list of namespace IDs. Enabled gadgets will only load when the
viewed page is in one of the required namespaces.
Bug: T204201
Bug: T63007
Change-Id: I7f797e35352b242ad78704074e98c6569a1adf91
Gadgets can mark themselves as ES6-only by specifying the requiresES6
boolean attribute. Syntax validation is disabled for them (as the
validator doesn't support ES6 yet), and they are loaded together in a
separate request.
The minifier doesn't reject syntax errors, and thus these would
be passed through to web clients. Hence, communities using this feature
are encouraged to use ESLint or another linter to make sure only
valid ES <= 6 code is being used.
Because of the above, this feature is only made available for
non-default gadgets.
Bug: T75714
Change-Id: Ib98ac0700471554d5721d7ab858d4660e1e0e980
