IDL Compiler: Validate extended attributes in dictionaries and callback functions

IDL Compiler has been ignoring the validity of extended attributes on
dictionaries, callback functions, and their membmers.
This CL makes to do it.

Bug: 999690
Change-Id: Idcb88c6a346989e553a3bbe23e1273e00f8a04da
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1781902
Commit-Queue: Hitoshi Yoshida <peria@chromium.org>
Reviewed-by: Yuki Shiino <yukishiino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#695033}

third_party/blink/renderer/bindings/scripts/idl_validator.py

@@ -60,6 +60,15 @@ class IDLExtendedAttributeValidator(object):
                 self.validate_extended_attributes_node(operation)
                 for argument in operation.arguments:
                     self.validate_extended_attributes_node(argument)
+        for dictionary in definitions.dictionaries.itervalues():
+            self.validate_extended_attributes_node(dictionary)
+            for member in dictionary.members:
+                self.validate_extended_attributes_node(member)
+        for callback_function in definitions.callback_functions.itervalues():
+            self.validate_extended_attributes_node(callback_function)
+            for argument in callback_function.arguments:
+                self.validate_extended_attributes_node(argument)
+
 
     def validate_extended_attributes_node(self, node):
         for name, values_string in node.extended_attributes.iteritems():