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

Source/bindings/scripts/v8_interface.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 454 matching lines @@
         counter[item] += 1
     return counter
 
 
 ################################################################################
 # Constructors
 ################################################################################
 
 # [Constructor]
 def generate_constructor(interface, constructor):
+    generated_arguments = [v8_methods.generate_argument(interface, constructor, argument, index)
+                           for index, argument in enumerate(constructor.arguments)]
+
     return {
         'argument_list': constructor_argument_list(interface, constructor),
-        'arguments': [v8_methods.generate_argument(interface, constructor, argument, index)
-                      for index, argument in enumerate(constructor.arguments)],
+        'arguments': generated_arguments,
+        'arguments_need_try_catch': any(
+            v8_methods.argument_needs_try_catch(argument)
+            for argument in generated_arguments),
         '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 248 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)