This avoids a lot of mismatches between nsAString and char16_t*, thus removing
many getter_Copies() and ToNewUnicode() and get() calls, and generally making
things simpler.
Note: the patch removes GetDefaultPrinterNameFromGlobalPrinters() by simply
inlining it at its two callsites, which is easy with the changed types.
--HG--
extra : rebase_source : 9ab9b3694f093fc9b22c7f8e2394a98674d76c11