1216351 - Consider autopopulating "subproperties" list for aliases, in property_database.js

Status: NEW

(Core :: CSS Parsing and Computation, defect)

Description

[Daniel Holbert [:dholbert]]

As noted in bug 1212191 comment 5, we could condense property_database.js a bit if we autopopulated the "subproperties" list for aliases.

In particular:
 - For true shorthands, we can copy the subproperties list from the aliased property.
 - Otherwise, we can just make subproperties a singleton array containing the same value as the "alias_for" field. (The name of the aliased property.)

This has the upside of making it easier to add aliases, and the slight downside of making this list a little more magical & a little less declarative.  I think the upside outweighs the downside, though.  (This is also a logical extension of bug 1210905.)