Bug 935220: Uplift Add-on SDK to Firefox. r=me

https://github.com/mozilla/addon-sdk/compare/firefox27...50697e6182cb4f79f9605b7cd1d1f5084cfaf03f

addon-sdk/source/python-lib/cuddlefish/manifest.py

@@ -606,9 +606,13 @@ class ManifestBuilder:
         filename = os.sep.join(name.split("/"))
         # normalize filename, make sure that we do not add .js if it already has
         # it.
-        if not filename.endswith(".js"):
+        if not filename.endswith(".js") and not filename.endswith(".json"):
           filename += ".js"
-        basename = filename[:-3]
+
+        if filename.endswith(".js"):
+          basename = filename[:-3]
+        if filename.endswith(".json"):
+          basename = filename[:-5]
 
         pkg = self.pkg_cfg.packages[pkgname]
         if isinstance(sections, basestring):