IDL: Add support for serializer definitions

tools/idl_parser/test_parser/interface_web.idl

Index: tools/idl_parser/test_parser/interface_web.idl
diff --git a/tools/idl_parser/test_parser/interface_web.idl b/tools/idl_parser/test_parser/interface_web.idl
index b1f3278623f8e4e764f5070dc8f495ff73fc1da9..90b0e83e8433707692fc00457aed1dfe056d0f6b 100644
--- a/tools/idl_parser/test_parser/interface_web.idl
+++ b/tools/idl_parser/test_parser/interface_web.idl
@@ -323,3 +323,49 @@ interface MyIfaceSetlike {
   readonly setlike<long>;
   setlike<double>;
 };
+
+/* TREE
+ *Interface(MyIfaceSerializer)
+ *  Serializer()
+ *  Serializer()
+ *    Operation(toJSON)
+ *      Arguments()
+ *      Type()
+ *        Any()
+ *  Serializer()
+ *  Serializer()
+ *    Map()
+ *  Serializer()
+ *    Map()
+ *  Serializer()
+ *    Map()
+ *  Serializer()
+ *    Map()
+ *  Serializer()
+ *    Map()
+ *  Serializer()
+ *    Map()
+ *  Serializer()
+ *    Map()
+ *  Serializer()
+ *    List()
+ *  Serializer()
+ *    List()
+ *  Serializer()
+ *    List()
+ */
+interface MyIfaceSerializer {
+  serializer;
+  serializer any toJSON();
+  serializer = name;
+  serializer = {};
+  serializer = { getter };
+  serializer = { attribute };
+  serializer = { inherit, attribute };
+  serializer = { inherit };
+  serializer = { inherit, name1, name2 };
+  serializer = { name1, name2 };
+  serializer = [];
+  serializer = [getter];
+  serializer = [name1, name2];
+};