IDL compiler: Support multi-layered extended attributes

Adds IdlType.effective_annotations, which supports multi-layered
extended attributes.  For example, given the following IDL
fragments,

  typedef [ExtAttr1] long NewLong;
  void f([ExtAttr2] NewLong arg);

arg.idl_type.effective_annotations returns [ExtAttr1, ExtAttr2]
while arg.idl_type.extended_attributes returns [ExtAttr1] only.

c.f. https://crbug.com/1058762

Bug: 839389
Change-Id: I49cdd82dfa0b8c3468610ffce6458eec963d9148
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2096408Reviewed-by: Hitoshi Yoshida <peria@chromium.org>
Commit-Queue: Yuki Shiino <yukishiino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#749556}

third_party/blink/renderer/bindings/scripts/web_idl/idl_compiler.py

@@ -597,9 +597,10 @@ class IdlCompiler(object):
                 idl_def = StubUserDefinedType(ref.identifier)
             if isinstance(idl_def, UserDefinedType):
                 idl_type = self._idl_type_factory.definition_type(
-                    user_defined_type=idl_def)
+                    reference_type=ref, user_defined_type=idl_def)
             elif isinstance(idl_def, Typedef):
-                idl_type = self._idl_type_factory.typedef_type(typedef=idl_def)
+                idl_type = self._idl_type_factory.typedef_type(
+                    reference_type=ref, typedef=idl_def)
             else:
                 assert False
             ref.set_target_object(idl_type)

third_party/blink/renderer/bindings/scripts/web_idl/idl_type_test.py

@@ -54,7 +54,7 @@ class IdlTypesTest(unittest.TestCase):
         ext_attrs = ExtendedAttributes([ExtendedAttribute('Clamp')])
         annotated_type = factory.simple_type(
             'short', extended_attributes=ext_attrs)
-        self.assertTrue(annotated_type.is_annotated)
+        self.assertTrue(annotated_type.extended_attributes)
         self.assertTrue(annotated_type.is_numeric)
 
         optional_type = factory.simple_type('DOMString', is_optional=True)
@@ -63,7 +63,7 @@ class IdlTypesTest(unittest.TestCase):
 
         annotated_optional = factory.simple_type(
             'long', is_optional=True, extended_attributes=ext_attrs)
-        self.assertTrue(annotated_optional.is_annotated)
+        self.assertTrue(annotated_optional.extended_attributes)
         self.assertTrue(annotated_optional.is_optional)
         self.assertTrue(annotated_optional.is_numeric)