[DevTools] Simplify getting back to default network order.

Source/devtools/front_end/ui_lazy/DataGrid.js

Index: Source/devtools/front_end/ui_lazy/DataGrid.js
diff --git a/Source/devtools/front_end/ui_lazy/DataGrid.js b/Source/devtools/front_end/ui_lazy/DataGrid.js
index c312c0bd34c80c5d072e62fc0a102ec69ba707ac..9ac8aafb3d70b38a37222ae598b139e4b0509255 100644
--- a/Source/devtools/front_end/ui_lazy/DataGrid.js
+++ b/Source/devtools/front_end/ui_lazy/DataGrid.js
@@ -883,15 +883,6 @@ WebInspector.DataGrid.prototype = {
         this._sortColumnCell.classList.add(sortOrder);
     },
 
-    /**
-     * @param {string} columnIdentifier
-     * @return {!Element}
-     */
-    headerTableHeader: function(columnIdentifier)
-    {
-        return this._headerTableHeaders[columnIdentifier];
-    },
-
     _mouseDownInDataTable: function(event)
     {
         var gridNode = this.dataGridNodeFromNode(event.target);