code: function setVisible(curEditor, visible) {
          // short-circuit no-ops
          if ((visible && curEditor === editor) || (!visible && !editor)) {
              return;
          }
  
          if (visible) {
              console.assert(!editor);
              editor = curEditor;
  
              // Don't support inline editors yet - search inside them is pretty screwy anyway (#2110)
              if (editor.isTextSubset()) {
                  return;
              }
  
              var $sb = _getScrollbar(editor),
                  $overlay = $("<div class='tickmark-track'></div>");
              $sb.parent().append($overlay);
  
              _calcScaling();
  
              // Update tickmarks during editor resize (whenever resizing has paused/stopped for > 1/3 sec)
              WorkspaceManager.on("workspaceUpdateLayout.ScrollTrackMarkers", _.debounce(function () {
                  if (marks.length) {
                      _calcScaling();
                      $(".tickmark-track", editor.getRootElement()).empty();
                      _renderMarks(marks);
                  }
              }, 300));
  
          } else {
              console.assert(editor === curEditor);
              $(".tickmark-track", curEditor.getRootElement()).remove();
              editor = null;
              marks = [];
              WorkspaceManager.off("workspaceUpdateLayout.ScrollTrackMarkers");
          }
      }
docs: Add or remove the tickmark track from the editor's UI