Comment 102 for bug 747197

So, for what it's worth, the way I think this ought to be fixed is roughly as follows:

To avoid having two separate bits of CSS serialization code, we should teach the style system to serialize with URI fixup.

For a start, this requires the nsWebBrowserPersist code to implement an interface a lot like nsIDocumentEncoderNodeFixup -- except for URI fixup. In other words, the interface would take a URI as input (probably nsIURI) and return a URI as output (probably string), potentially enqueueing the saving of the URI in question as part of the implementation.

Then we could add a Serialize method to nsIStyleSheet that took one of these as an argument (but where the object being null would mean no URI fixup was needed). Furthermore, we would then add Serialize methods to everything that has a GetCssText method by renaming GetCssText and adding the argument to this new interface -- and then adding a GetCssText that called Serilaize(null) -- where the null object for this new interface would mean to do no URI fixup. This object would further have to be passed down through nsCSSDeclaration::ToString and the methods it calls -- where, again, null would mean that no fixup was needed.

I think this is highly preferable to reimplementing CSS parsing and serialization.

Boris, does this seem reasonable?