CHANGELOG.md in glimmer-2.7.8 vs CHANGELOG.md in glimmer-2.7.9

@@ -1,9 +1,13 @@
 # Change Log
 
 Related Change Logs:
 - [glimmer-dsl-swt/CHANGELOG.md](https://github.com/AndyObtiva/glimmer-dsl-swt/blob/master/CHANGELOG.md)
 
+### 2.7.9
+
+- Optimize performance of `Glimmer::DataBinding::ObservableModel#add_observer` by removing `OpenStruct` constant check.
+
 ### 2.7.8
 
 - Allow passing `BindExpression` only 1 argument (e.g. presenter.todos) or 1 argument + 1 hash (e.g. presenter.todos, on_read: -> {})
 - `ObserveExpression` always uses `ModelBinding` for arguments to leverage its advanced features, like nested/computed/indexed/keyed data-binding
 - In Opal, `ModelBinding` converters/hooks do not require an argument anymore (e.g. can invoke `after_write: -> { do_something }` without block args)