         (percentDone, patch) =>
           if patch and patch.getChangeCount() > 0
             changeEvent = new CompositeChangeEvent(@buffer, patch)
-            checkpoint = @history.createCheckpoint(@createMarkerSnapshot(), true)
+            checkpoint = @history.createCheckpoint(markerSnapshot: @createMarkerSnapshot(), isBarrier: true)
             @emitter.emit('will-reload')
             @emitter.emit('will-change', changeEvent)
       )

  #
  # Returns a checkpoint value.
  createCheckpoint: ->
    @history.createCheckpoint(@createMarkerSnapshot(), false)

  # Public: Revert the buffer to the state it was in when the given
  # checkpoint was created.

        if patch
          if patch.getChangeCount() > 0
            changeEvent = new CompositeChangeEvent(@buffer, patch)
            checkpoint = @history.createCheckpoint(markerSnapshot: @createMarkerSnapshot(), isBarrier: true)
            @emitter.emit('will-reload')
            @emitter.emit('will-change', changeEvent)
          else if options?.discardChanges
