message: Properly initialize KVOAdapter::track_all
  Using list-initialization for the base class zero-initializes the member
  variables, while the default constructor does not.
diff: @@ -55,7 +55,8 @@ private:
  };
  KVOAdapter::KVOAdapter(std::vector<BindingContext::ObserverState>& observers, BindingContext* context)
  -: m_context(context)
  +: _impl::TransactionChangeInfo{}
  +, m_context(context)
  , m_observers(observers)
  {
  if (m_observers.empty())
  