Restore abstract.patch which was mistakenly removed

components/script/dom/bindings/codegen/parser/abstract.patch

@@ -0,0 +1,12 @@
+--- WebIDL.py
++++ WebIDL.py
+@@ -1416,7 +1416,8 @@
+                   identifier == "LegacyEventInit" or
+                   identifier == "ProbablyShortLivingObject" or
+                   identifier == "LegacyUnenumerableNamedProperties" or
+-                  identifier == "NonOrdinaryGetPrototypeOf"):
++                  identifier == "NonOrdinaryGetPrototypeOf" or
++                  identifier == "Abstract"):
+                 # Known extended attributes that do not take values
+                 if not attr.noArguments():
+                     raise WebIDLError("[%s] must take no arguments" % identifier,