IDL: Support callback function types in overload resolution

Source/bindings/scripts/v8_interface.py

Index: Source/bindings/scripts/v8_interface.py
diff --git a/Source/bindings/scripts/v8_interface.py b/Source/bindings/scripts/v8_interface.py
index 7e86bcf1918321cf0d4c97be1d8d463f3c7e6cf4..96c83e4bcc2226bcbbde3eb501ebf1f78cccdfa7 100644
--- a/Source/bindings/scripts/v8_interface.py
+++ b/Source/bindings/scripts/v8_interface.py
@@ -842,12 +842,33 @@ def resolution_tests_methods(effective_overloads):
         test = 'V8{idl_type}::hasInstance({cpp_value}, info.GetIsolate())'.format(idl_type=idl_type.base_type, cpp_value=cpp_value)
         yield test, method
 
-    # 8. Otherwise: if V is any kind of object except for a native Date object,
+    # 13. Otherwise: if IsCallable(V) is true, and there is an entry in S that
+    # has one of the following types at position i of its type list,
+    # • a callback function type
+    # ...
+    #
+    # FIXME:
+    # We test for functions rather than callability, which isn't strictly the
+    # same thing.
+    try:
+        method = next(method for idl_type, method in idl_types_methods
+                      if idl_type.is_callback_function)
+        test = '%s->IsFunction()' % cpp_value
+        yield test, method
+    except StopIteration:
+        pass
+
+    # 14. Otherwise: if V is any kind of object except for a native Date object,
     # a native RegExp object, and there is an entry in S that has one of the
     # following types at position i of its type list,
-    # • an array type
     # • a sequence type
     # ...
+    #
+    # 15. Otherwise: if V is any kind of object except for a native Date object,
+    # a native RegExp object, and there is an entry in S that has one of the
+    # following types at position i of its type list,
+    # • an array type
+    # ...
     # • a dictionary
     #
     # FIXME: