Bug 1457749: Part 1 - Import RDFDataSource from McCoy and modernize. r=Mossop

MozReview-Commit-ID: 7y7kGE2kF9E

--HG--
extra : source : bef795f8c45c7cb33ab59c02348ad40e35660195

toolkit/mozapps/extensions/internal/moz.build

@@ -12,6 +12,7 @@ EXTRA_JS_MODULES.addons += [
     'GMPProvider.jsm',
     'LightweightThemeImageOptimizer.jsm',
     'ProductAddonChecker.jsm',
+    'RDFDataSource.jsm',
     'SpellCheckDictionaryBootstrap.js',
     'UpdateRDFConverter.jsm',
     'XPIDatabase.jsm',