toImplArguments should return HeapVector for Union types.

Source/bindings/scripts/v8_methods.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 353 matching lines @@
 def v8_value_to_local_cpp_variadic_value(method, argument, index, return_promise):
     assert argument.is_variadic
     idl_type = argument.idl_type
     this_cpp_type = idl_type.cpp_type
 
     if method.returns_promise:
         check_expression = 'exceptionState.hadException()'
     else:
         check_expression = 'exceptionState.throwIfNeeded()'
 
+    if idl_type.is_dictionary or idl_type.is_union_type:

[haraken, 2015/05/27 11:45:05]

bashi-san: Would it make more sense to set idl_type.is_garbage_collected for IDL
dictionaries and union types and use it here?

[bashi, 2015/05/28 01:36:49]

either is fine for me.

+        vector_type = 'HeapVector'
+    else:
+        vector_type = 'Vector'
+
     return {
-        'assign_expression': 'toImplArguments<%s>(info, %s, exceptionState)' % (this_cpp_type, index),
+        'assign_expression': 'toImplArguments<%s<%s>>(info, %s, exceptionState)' % (vector_type, this_cpp_type, index),
         'check_expression': check_expression,
         'cpp_type': this_cpp_type,
         'cpp_name': argument.name,
         'declare_variable': False,
     }
 
 
 def v8_value_to_local_cpp_value(method, argument, index, return_promise=False, restricted_float=False):
     extended_attributes = argument.extended_attributes
     idl_type = argument.idl_type
@@ skipping 72 matching lines @@
     return method.idl_type and method.idl_type.name == 'Promise'
 
 IdlOperation.returns_promise = property(method_returns_promise)
 
 
 def argument_conversion_needs_exception_state(method, argument):
     idl_type = argument.idl_type
     return (idl_type.v8_conversion_needs_exception_state or
             argument.is_variadic or
             (method.returns_promise and idl_type.is_string_type))