Create fewer local v8::TryCatch objects in generated bindings code

Source/bindings/scripts/v8_interface.py

 # Copyright (C) 2013 Google Inc. All rights reserved.
 # coding=utf-8
 #
 # 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
@@ skipping 732 matching lines @@
     l.sort(key=key)
     return ((k, list(g)) for k, g in itertools.groupby(l, key))
 
 
 ################################################################################
 # Constructors
 ################################################################################
 
 # [Constructor]
 def generate_constructor(interface, constructor):
+    arguments_need_try_catch = any(v8_methods.argument_needs_try_catch(argument)
+                                   for argument in constructor.arguments)
+
     return {
         'argument_list': constructor_argument_list(interface, constructor),
-        'arguments': [v8_methods.generate_argument(interface, constructor, argument, index)
+        'arguments': [v8_methods.generate_argument(interface, constructor, argument, index, arguments_need_try_catch)
                       for index, argument in enumerate(constructor.arguments)],
+        'arguments_need_try_catch': arguments_need_try_catch,
         'cpp_type': cpp_template_type(
             cpp_ptr_type('RefPtr', 'RawPtr', gc_type(interface)),
             cpp_name(interface)),
         'has_exception_state':
             # [RaisesException=Constructor]
             interface.extended_attributes.get('RaisesException') == 'Constructor' or
             any(argument for argument in constructor.arguments
                 if argument.idl_type.name == 'SerializedScriptValue' or
                    argument.idl_type.is_integer_type),
         'is_constructor': True,
@@ skipping 236 matching lines @@
         deleter = next(
             method
             for method in interface.operations
             if ('deleter' in method.specials and
                 len(method.arguments) == 1 and
                 str(method.arguments[0].idl_type) == 'DOMString'))
     except StopIteration:
         return None
 
     return property_deleter(deleter)