bindings: Throw exceptions when required dictionary members aren't passed

third_party/WebKit/Source/bindings/scripts/v8_dictionary.py

Index: third_party/WebKit/Source/bindings/scripts/v8_dictionary.py
diff --git a/third_party/WebKit/Source/bindings/scripts/v8_dictionary.py b/third_party/WebKit/Source/bindings/scripts/v8_dictionary.py
index 9917b2aeca18b99d184d89f7a3e55c10d5422f52..dde7e1ce6ae3ebc43eb9d3c9506c7df6f5dc133a 100644
--- a/third_party/WebKit/Source/bindings/scripts/v8_dictionary.py
+++ b/third_party/WebKit/Source/bindings/scripts/v8_dictionary.py
@@ -60,6 +60,9 @@ def dictionary_context(dictionary, interfaces_info):
         'members': [member_context(dictionary, member)
                     for member in sorted(dictionary.members,
                                          key=operator.attrgetter('name'))],
+        'required_member_names': sorted([member.name
+                                         for member in dictionary.members
+                                         if member.is_required]),
         'use_permissive_dictionary_conversion': 'PermissiveDictionaryConversion' in dictionary.extended_attributes,
         'v8_class': v8_types.v8_type(cpp_class),
         'v8_original_class': v8_types.v8_type(dictionary.name),