[Devtools] Cleanup DataGrid's typecast and identifier naming

third_party/WebKit/Source/devtools/front_end/network/NetworkLogViewColumns.js

 // 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.
 
 /**
  * @constructor
  * @param {!WebInspector.NetworkLogView} networkLogView
  * @param {!WebInspector.Setting} networkLogLargeRowsSetting
  */
 WebInspector.NetworkLogViewColumns = function(networkLogView, networkLogLargeRowsSetting)
@@ skipping 436 matching lines @@
         }
     },
 
     sortByCurrentColumn: function()
     {
         this._sortHandler();
     },
 
     _sortHandler: function()
     {
-        var columnIdentifier = this._dataGrid.sortColumnIdentifier();
-        var columnConfig = this._columns.find(columnConfig => columnConfig.id === columnIdentifier);
+        var columnId = this._dataGrid.sortColumnId();
+        var columnConfig = this._columns.find(columnConfig => columnConfig.id === columnId);
         if (!columnConfig)
             return;
         if (columnConfig.sortConfig && columnConfig.sortConfig.entries) {
             this._sortByDropdownItem(columnConfig);
             return;
         }
         if (!columnConfig.sortConfig.sortingFunction)
             return;
 
         this._networkLogView.removeAllNodeHighlights();
@@ skipping 362 matching lines @@
             divider.element.classList.toggle("network-frame-divider-selected", false);
     },
 
     _updateRowsSize: function()
     {
         if (Runtime.experiments.isEnabled("canvasNetworkTimeline"))
             return;
         this._timelineGrid.element.classList.toggle("small", !this._networkLogLargeRowsSetting.get());
     }
 };