Recursively try to find an existing notification method to fire the PropertyChanged event.

FindNotificationMethod.cs

private static MethodDefinition FindNotificationMethod(
  TypeDefinition typeDef, 
  bool includePrivateMethods = true)
{
  foreach (var m in typeDef.Methods.Where(m => includePrivateMethods 
    || m.Attributes.HasFlag(MethodAttributes.Public)))
  {
    if (IsProbableNotificationMethod(m))
    {
      return m;
    }
  }
  var baseTypeRef = typeDef.BaseType;
  if (baseTypeRef.FullName != "System.Object")
  {
    return FindNotificationMethod(baseTypeRef.Resolve(), false);
  } 
  return null;
}

private static bool IsProbableNotificationMethod(
  MethodDefinition methodDef)
{
  return methodDef.HasBody 
   && IsProbableNotificationMethodWithBody(methodDef);
}

private static bool IsProbableNotificationMethodWithBody(
  MethodDefinition methodDef)
{
  foreach (var insn in methodDef.Body.Instructions)
  {
    if (insn.OpCode == OpCodes.Callvirt)
    {
      var callee = (MethodReference) insn.Operand;
      if (callee.Name == "Invoke" 
        && callee.DeclaringType.Name == "PropertyChangedEventHandler")
      {
        return true;
      }
    }    
  }
  return false;
}