Bug 276431 moved nsSVGUtils::ConvertToSurfaceSize from the .cpp file to the .h file, so that it can be called from imagelib in non-libxul builds:
Once we move to a libxul-only world, that method can & should move back to the .cpp file.
This was done in bug 649429, but I can't dupe it because I can't access that bug. Could you?
Thanks for pointing that out. Resolving as FIXED with a dependency on that bug. (Not duping since the main thrust of that bug was completely different from this.)
The checkin from that bug that fixed this was: