diff --git a/static/js/tracker/externs.js b/static/js/tracker/externs.js
new file mode 100644
index 0000000..2a92f58
--- /dev/null
+++ b/static/js/tracker/externs.js
@@ -0,0 +1,115 @@
+/* Copyright 2016 The Chromium Authors. All Rights Reserved.
+ *
+ * Use of this source code is governed by a BSD-style
+ * license that can be found in the LICENSE file or at
+ * https://developers.google.com/open-source/licenses/bsd
+ */
+/* eslint-disable no-var */
+
+// Defined in framework/js:core_scripts
+var _hideID;
+var _showID;
+var _hideEl;
+var _showEl;
+var _showInstead;
+var _toggleHidden;
+
+var _selectAllIssues;
+var _selectNoneIssues;
+
+var _toggleRows;
+var _toggleColumn;
+var _toggleColumnUpdate;
+var _addGroupBy;
+var _addcol;
+var _checkRangeSelect;
+var _setRowLinks;
+var _makeIssueLink;
+
+var _onload;
+
+var _handleListActions;
+var _handleDetailActions;
+
+var _loadStatusSelect;
+var _fetchOptions;
+var _setACOptions;
+var _openIssueUpdateForm;
+var _addAttachmentFields;
+var _ignoreWidgetIfOpIsClear;
+
+var _formatContextQueryArgs;
+var _ctxArgs;
+var _ctxCan;
+var _ctxQuery;
+var _ctxSortspec;
+var _ctxGroupBy;
+var _ctxDefaultColspec;
+var _ctxStart;
+var _ctxNum;
+var _ctxResultsPerPage;
+
+var _filterTo;
+var _sortUp;
+var _sortDown;
+
+var _closeAllPopups;
+var _closeSubmenus;
+var _showRight;
+var _showBelow;
+var _highlightRow;
+var _highlightRowCallback;
+var _allColumnNames;
+
+var _setFieldIDs;
+var _selectTemplate;
+var _saveTemplate;
+var _newTemplate;
+var _deleteTemplate;
+var _switchTemplate;
+var _templateNames;
+
+var _confirmNovelStatus;
+var _confirmNovelLabel;
+var _lfidprefix;
+var _allOrigLabels;
+var _vallab;
+var _exposeExistingLabelFields;
+var _confirmDiscardEntry;
+var _confirmDiscardUpdate;
+var _checkPlusOne;
+var _checkUnrestrict;
+
+var _clearOnFirstEvent;
+var _forceProperTableWidth;
+
+var _acof;
+var _acmo;
+var _acse;
+var _acstore;
+var _acreg;
+var _accomp;
+var _acrob;
+
+var _d;
+
+var _getColspec;
+
+var issueRefs;
+
+var kibbles;
+var _setupKibblesOnEntryPage;
+var _setupKibblesOnListPage;
+var _setupKibblesOnDetailPage;
+
+var CS_env;
+
+var _checkFieldNameOnServer;
+var _checkLeafName;
+
+var _addMultiFieldValueWidget;
+var _removeMultiFieldValueWidget;
+var console;
+var _trimCommas;
+
+var _initDragAndDrop;