diff -r 000000000000 -r 6474c204b198 dom/bindings/GenerateCSS2PropertiesWebIDL.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/bindings/GenerateCSS2PropertiesWebIDL.py	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,35 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this file,
+# You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import sys
+import string
+
+propList = eval(sys.stdin.read())
+props = ""
+for [prop, id, flags, pref] in propList:
+    extendedAttrs = ["Throws", "TreatNullAs=EmptyString"]
+    # To limit the overhead of Func= annotations, we only generate them when
+    # necessary, which is when the
+    # CSS_PROPERTY_ALWAYS_ENABLED_IN_CHROME_OR_CERTIFIED_APP flag is set.
+    # Otherwise, we try to get by with just a Pref= annotation or no annotation
+    # at all.
+    if "CSS_PROPERTY_ALWAYS_ENABLED_IN_CHROME_OR_CERTIFIED_APP" in flags:
+        extendedAttrs.append('Func="IsCSSPropertyExposedToJS<eCSSProperty_%s>"' % id)
+    # The following is an 'elif' because it is the responsibility of
+    # IsCSSPropertyExposedToJS to handle the pref if there is one.
+    elif pref is not "":
+        extendedAttrs.append('Pref="%s"' % pref)
+    if not prop.startswith("Moz"):
+        prop = prop[0].lower() + prop[1:]
+    # Unfortunately, even some of the getters here are fallible
+    # (e.g. on nsComputedDOMStyle).
+    props += "  [%s] attribute DOMString %s;\n" % (", ".join(extendedAttrs),
+                                                   prop)
+
+idlFile = open(sys.argv[1], "r");
+idlTemplate = idlFile.read();
+idlFile.close();
+
+print ("/* THIS IS AN AUTOGENERATED FILE.  DO NOT EDIT */\n\n" +
+       string.Template(idlTemplate).substitute({ "props": props }))