initialize result variables in v8 bindings

Source/bindings/scripts/v8_types.py

 # Copyright (C) 2013 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 172 matching lines @@
         implemented_as_class = idl_type.implemented_as
         if raw_type:
             return implemented_as_class + '*'
         new_type = 'Member' if used_in_cpp_sequence else 'RawPtr'
         ptr_type = cpp_ptr_type(('PassRefPtr' if used_as_argument else 'RefPtr'), new_type, idl_type.gc_type)
         return cpp_template_type(ptr_type, implemented_as_class)
     # Default, assume native type is a pointer with same type name as idl type
     return base_idl_type + '*'
 
 
+def cpp_type_initializer(idl_type):
+    """Returns a string containing a C++ initialization statement for the
+    corresponding type.
+
+    |idl_type| argument is of type IdlType.
+    """
+
+    if (idl_type.is_numeric_type):
+        return ' = 0'
+    if idl_type.base_type == 'boolean':
+        return ' = false'
+    return ''
+
+
 def cpp_type_union(idl_type, extended_attributes=None, raw_type=False):
     return (member_type.cpp_type for member_type in idl_type.member_types)
 
 
+def cpp_type_initializer_union(idl_type):
+    return (member_type.cpp_type_initializer for member_type in idl_type.member_types)
+
+
 # Allow access as idl_type.cpp_type if no arguments
 IdlType.cpp_type = property(cpp_type)
+IdlType.cpp_type_initializer = property(cpp_type_initializer)
 IdlUnionType.cpp_type = property(cpp_type_union)
+IdlUnionType.cpp_type_initializer = property(cpp_type_initializer_union)
 IdlType.cpp_type_args = cpp_type
 IdlUnionType.cpp_type_args = cpp_type_union
 
 
 def cpp_template_type(template, inner_type):
     """Returns C++ template specialized to type, with space added if needed."""
     if inner_type.endswith('>'):
         format_string = '{template}<{inner_type} >'
     else:
         format_string = '{template}<{inner_type}>'
@@ skipping 531 matching lines @@
 
 def is_explicit_nullable(idl_type):
     # Nullable type that isn't implicit nullable (see above.) For such types,
     # we use Nullable<T> or similar explicit ways to represent a null value.
     return idl_type.is_nullable and not idl_type.is_implicit_nullable
 
 IdlType.is_implicit_nullable = property(is_implicit_nullable)
 IdlType.is_explicit_nullable = property(is_explicit_nullable)
 IdlUnionType.is_implicit_nullable = False
 IdlUnionType.is_explicit_nullable = property(is_explicit_nullable)