[Devtools] Cleanup DataGrid's typecast and identifier naming

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

 /*
  * Copyright (C) 2012 Research In Motion Limited. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 13 matching lines @@
 WebInspector.ResourceWebSocketFrameView = function(request)
 {
     WebInspector.VBox.call(this);
     this.registerRequiredCSS("network/webSocketFrameView.css");
     this.element.classList.add("websocket-frame-view");
     this._request = request;
 
     this._splitWidget = new WebInspector.SplitWidget(false, true, "resourceWebSocketFrameSplitViewState");
     this._splitWidget.show(this.element);
 
-    var columns = [
+    var columns = /** @type {!Array<!WebInspector.DataGrid.ColumnDescriptor>} */ ([
         {id: "data", title: WebInspector.UIString("Data"), sortable: false, weight: 88},
         {id: "length", title: WebInspector.UIString("Length"), sortable: false, align: WebInspector.DataGrid.Align.Right, weight: 5},
         {id: "time", title: WebInspector.UIString("Time"), sortable: true, weight: 7}
-    ];
+    ]);
 
     this._dataGrid = new WebInspector.SortableDataGrid(columns, undefined, undefined, undefined, this._onContextMenu.bind(this));
     this._dataGrid.setStickToBottom(true);
     this._dataGrid.setCellClass("websocket-frame-view-td");
     this._timeComparator = /** @type {!WebInspector.SortableDataGrid.NodeComparator} */ (WebInspector.ResourceWebSocketFrameNodeTimeComparator);
     this._dataGrid.sortNodes(this._timeComparator, false);
     this._dataGrid.markColumnAsSortedBy("time", WebInspector.DataGrid.Order.Ascending);
     this._dataGrid.addEventListener(WebInspector.DataGrid.Events.SortingChanged, this._sortItems, this);
 
     this._dataGrid.setName("ResourceWebSocketFrameView");
@@ skipping 201 matching lines @@
 
 /**
  * @param {!WebInspector.ResourceWebSocketFrameNode} a
  * @param {!WebInspector.ResourceWebSocketFrameNode} b
  * @return {number}
  */
 WebInspector.ResourceWebSocketFrameNodeTimeComparator = function(a, b)
 {
     return a._frame.time - b._frame.time;
 };