IDL: reuse more code between CG for methods and constructors

Source/bindings/scripts/v8_methods.py

Index: Source/bindings/scripts/v8_methods.py
diff --git a/Source/bindings/scripts/v8_methods.py b/Source/bindings/scripts/v8_methods.py
index dfb8460f0c3f6d8bc594efa8f0b424607978d6d5..9538b2c26da21129407eb2dc4dfc1ac88a436a1f 100644
--- a/Source/bindings/scripts/v8_methods.py
+++ b/Source/bindings/scripts/v8_methods.py
@@ -237,7 +237,12 @@ def cpp_value(interface, method, number_of_arguments):
 
     # Truncate omitted optional arguments
     arguments = method.arguments[:number_of_arguments]
-    cpp_arguments = v8_utilities.call_with_arguments(method)
+    cpp_arguments = []
+    if method.is_constructor:
+        call_with_values = interface.extended_attributes.get('ConstructorCallWith')
+    else:
+        call_with_values = method.extended_attributes.get('CallWith')
+    cpp_arguments.extend(v8_utilities.call_with_arguments(call_with_values))
     # Members of IDL partial interface definitions are implemented in C++ as
     # static member functions, which for instance members (non-static members)
     # take *impl as their first argument
@@ -249,7 +254,9 @@ def cpp_value(interface, method, number_of_arguments):
     if this_union_arguments:
         cpp_arguments.extend(this_union_arguments)
 
-    if 'RaisesException' in method.extended_attributes:
+    if ('RaisesException' in method.extended_attributes or
+        (method.is_constructor and
+         has_extended_attribute_value(interface, 'RaisesException', 'Constructor'))):
         cpp_arguments.append('exceptionState')
 
     if method.name == 'Constructor':