IDL: Add toRestricted{Float,Double}() helpers to V8Binding.h

Source/bindings/scripts/v8_dictionary.py

Index: Source/bindings/scripts/v8_dictionary.py
diff --git a/Source/bindings/scripts/v8_dictionary.py b/Source/bindings/scripts/v8_dictionary.py
index 5598cdb9bf100741595277fe9be5640f0ccca33a..f6a05787ce9cf6fbd778b0bf197530a2bd0eebc0 100644
--- a/Source/bindings/scripts/v8_dictionary.py
+++ b/Source/bindings/scripts/v8_dictionary.py
@@ -11,6 +11,7 @@ from idl_types import IdlType
 from v8_globals import includes
 import v8_types
 import v8_utilities
+from v8_utilities import has_extended_attribute_value
 
 
 DICTIONARY_H_INCLUDES = frozenset([
@@ -56,7 +57,7 @@ def dictionary_context(dictionary, interfaces_info):
     context = {
         'cpp_class': cpp_class,
         'header_includes': set(DICTIONARY_H_INCLUDES),
-        'members': [member_context(member)
+        'members': [member_context(dictionary, member)
                     for member in sorted(dictionary.members,
                                          key=operator.attrgetter('name'))],
         'use_permissive_dictionary_conversion': 'PermissiveDictionaryConversion' in dictionary.extended_attributes,
@@ -74,11 +75,15 @@ def dictionary_context(dictionary, interfaces_info):
     return context
 
 
-def member_context(member):
+def member_context(dictionary, member):
     idl_type = member.idl_type
     idl_type.add_includes_for_type()
     unwrapped_idl_type = unwrap_nullable_if_needed(idl_type)
 
+    restricted_float = (
+        has_extended_attribute_value(dictionary, 'TypeChecking', 'Unrestricted') or
+        has_extended_attribute_value(member, 'TypeChecking', 'Unrestricted'))
+
     def default_values():
         if not member.default_value:
             return None, None
@@ -115,7 +120,7 @@ def member_context(member):
         'v8_default_value': v8_default_value,
         'v8_value_to_local_cpp_value': unwrapped_idl_type.v8_value_to_local_cpp_value(
             member.extended_attributes, member.name + 'Value',
-            member.name, isolate='isolate'),
+            member.name, isolate='isolate', restricted_float=restricted_float),
     }