Defining nsINSSComponent in idl rather than manually in a header file allows us
to make full use of the machinery that already exists to process and generate
the correct definitions. Furthermore, it enables us to define JS-accessible APIs
on nsINSSComponent, which enables us to build frontend features that can work
directly with the data and functionality the underlying implementation has
access to.
MozReview-Commit-ID: JFI9s12wmRE
--HG--
extra : rebase_source : 16b660e37db681c8823cbb6b7ff59dd0d35f7e73
