IDL: Drop redundant null check for string and wrapper type attributes

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 540 matching lines @@
         return 'array'
 
     # Simple types
     base_idl_type = idl_type.base_type
     # Basic types, without additional includes
     if base_idl_type in CPP_INT_TYPES:
         return 'int'
     if base_idl_type in CPP_UNSIGNED_TYPES:
         return 'unsigned'
     if idl_type.is_string_type:
+        if idl_type.is_nullable:
+            return 'StringOrNull'
         if 'TreatReturnedNullStringAs' not in extended_attributes:
             return base_idl_type
         treat_returned_null_string_as = extended_attributes['TreatReturnedNullStringAs']
         if treat_returned_null_string_as == 'Null':
             return 'StringOrNull'
         if treat_returned_null_string_as == 'Undefined':
             return 'StringOrUndefined'
         raise 'Unrecognized TreatReturnNullStringAs value: "%s"' % treat_returned_null_string_as
     if idl_type.is_basic_type or base_idl_type == 'ScriptValue':
         return base_idl_type
@@ skipping 98 matching lines @@
     'ByteString': 'v8String({isolate}, {cpp_value})',
     'ScalarValueString': 'v8String({isolate}, {cpp_value})',
     'boolean': 'v8Boolean({cpp_value}, {isolate})',
     'int': 'v8::Integer::New({isolate}, {cpp_value})',
     'unsigned': 'v8::Integer::NewFromUnsigned({isolate}, {cpp_value})',
     'float': 'v8::Number::New({isolate}, {cpp_value})',
     'unrestricted float': 'v8::Number::New({isolate}, {cpp_value})',
     'double': 'v8::Number::New({isolate}, {cpp_value})',
     'unrestricted double': 'v8::Number::New({isolate}, {cpp_value})',
     'void': 'v8Undefined()',
+    # [TreatNullReturnValueAs]
+    'StringOrNull': '{cpp_value}.isNull() ? v8::Handle<v8::Value>(v8::Null({isolate})) : v8String({isolate}, {cpp_value})',
+    'StringOrUndefined': '{cpp_value}.isNull() ? v8Undefined() : v8String({isolate}, {cpp_value})',
     # Special cases
     'EventHandler': '{cpp_value} ? v8::Handle<v8::Value>(V8AbstractEventListener::cast({cpp_value})->getListenerObject(impl->executionContext())) : v8::Handle<v8::Value>(v8::Null({isolate}))',
     'ScriptValue': '{cpp_value}.v8Value()',
     'SerializedScriptValue': '{cpp_value} ? {cpp_value}->deserialize() : v8::Handle<v8::Value>(v8::Null({isolate}))',
     # General
     'array': 'v8Array({cpp_value}, {creation_context}, {isolate})',
     'DOMWrapper': 'toV8({cpp_value}, {creation_context}, {isolate})',
 }
 
 
@@ skipping 11 matching lines @@
 
 def literal_cpp_value(idl_type, idl_literal):
     """Converts an expression that is a valid C++ literal for this type."""
     # FIXME: add validation that idl_type and idl_literal are compatible
     literal_value = str(idl_literal)
     if idl_type.base_type in CPP_UNSIGNED_TYPES:
         return literal_value + 'u'
     return literal_value
 
 IdlType.literal_cpp_value = literal_cpp_value