If you’re working on Gecko, or Firefox, or Thunderbird, or really anything in the Mozilla universe that may impact developer documentation, there are a couple of things you can do to ensure that the relevant changes to developer documentation take place.
I mention this periodically in several forums, but it can’t be said often enough, so here we go:
First, if there’s a bug related to your work, make sure the “dev-doc-needed” keyword is added to the bug in Bugzilla. It doesn’t matter if you’ve actually made the change or not. The writers only apply changes to the documentation once the bug is both tagged as “dev-doc-needed” and the bug is marked as fixed. Until then, we pretty much ignore it.
Second, make sure the change that impacts developers is clearly explained somewhere in the bug comments. If necessary, add a new comment that explains what’s changed and why it’s relevant to developers, or at least says “Comments X, Y, and Z are relevant to developers.” This will reduce the likelihood that we’ll have to hunt people down and ask a lot of questions in order to ensure that the stuff gets written up adequately.
Third, if there isn’t really a good bug in Bugzilla on what needs to be written, feel free to file a new bug against the Mozilla Developer Center’s Documentation Requests component, explaining what needs to be written up. Useful information here includes links to the files that have changed (especially IDL), multiple relevant bugs, etc.
In all cases, including information about who would best be able to answer questions about the topic would be extremely helpful.
You can pretty safely assume that if your material isn’t either tagged as “dev-doc-needed” or filed as a bug against MDC, it won’t get written about. The sooner either of these is done in the development cycle for a given release, the more likely you are to get good documentation written, because this helps me schedule writing work to ensure that there’s time allotted for everything.