DevTools: DataGrid: remove duplicated implementaion of nodes sorting.

Source/devtools/front_end/resources/DirectoryContentView.js

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 51 matching lines @@
     showEntries: function(entries)
     {
         const indexes = WebInspector.DirectoryContentView.columnIndexes;
         this.rootNode().removeChildren();
         for (var i = 0; i < entries.length; ++i)
             this.rootNode().appendChild(new WebInspector.DirectoryContentView.Node(entries[i]));
     },
 
     _sort: function()
     {
-        var column = /** @type {string} */ (this.sortColumnIdentifier());
-        this.sortNodes(WebInspector.DirectoryContentView.Node.comparator(column, !this.isSortOrderAscending()), false);
+        var column = this.sortColumnIdentifier();
+        if (!column)
+            return;
+        this.sortNodes(WebInspector.DirectoryContentView.Node.comparator(column), !this.isSortOrderAscending());
     },
 
     __proto__: WebInspector.DataGrid.prototype
 }
 
 /**
  * @constructor
  * @extends {WebInspector.DataGridNode}
  * @param {!WebInspector.FileSystemModel.Entry} entry
  */
 WebInspector.DirectoryContentView.Node = function(entry)
 {
     const indexes = WebInspector.DirectoryContentView.columnIndexes;
     var data = {};
     data[indexes.Name] = entry.name;
     data[indexes.URL] = entry.url;
     data[indexes.Type] = entry.isDirectory ? WebInspector.UIString("Directory") : entry.mimeType;
     data[indexes.Size] = "";
     data[indexes.ModificationTime] = "";
 
     WebInspector.DataGridNode.call(this, data);
     this._entry = entry;
     this._metadata = null;
 
     this._entry.requestMetadata(this._metadataReceived.bind(this));
 }
 
 /**
  * @param {string} column
- * @param {boolean} reverse
- * @return {function(!WebInspector.DirectoryContentView.Node, !WebInspector.DirectoryContentView.Node):number|undefined}
+ * @return {function(!WebInspector.DataGridNode, !WebInspector.DataGridNode):number}
  */
-WebInspector.DirectoryContentView.Node.comparator = function(column, reverse)
+WebInspector.DirectoryContentView.Node.comparator = function(column)
 {
-    var reverseFactor = reverse ? -1 : 1;
     const indexes = WebInspector.DirectoryContentView.columnIndexes;
 
     switch (column) {
     case indexes.Name:
     case indexes.URL:
         return function(x, y)
         {
             return isDirectoryCompare(x, y) || nameCompare(x, y);
         };
     case indexes.Type:
         return function(x, y)
         {
             return isDirectoryCompare(x ,y) || typeCompare(x, y) || nameCompare(x, y);
         };
     case indexes.Size:
         return function(x, y)
         {
             return isDirectoryCompare(x, y) || sizeCompare(x, y) || nameCompare(x, y);
         };
     case indexes.ModificationTime:
         return function(x, y)
         {
             return isDirectoryCompare(x, y) || modificationTimeCompare(x, y) || nameCompare(x, y);
         };
+    default:
+        return WebInspector.DataGrid.TrivialComparator;
     }
 
     function isDirectoryCompare(x, y)
     {
         if (x._entry.isDirectory != y._entry.isDirectory)
             return y._entry.isDirectory ? 1 : -1;
         return 0;
     }
 
     function nameCompare(x, y)
     {
-        return reverseFactor * x._entry.name.compareTo(y._entry.name);
+        return x._entry.name.compareTo(y._entry.name);
     }
 
     function typeCompare(x, y)
     {
-        return reverseFactor * (x._entry.mimeType || "").compareTo(y._entry.mimeType || "");
+        return (x._entry.mimeType || "").compareTo(y._entry.mimeType || "");
     }
 
     function sizeCompare(x, y)
     {
-        return reverseFactor * ((x._metadata ? x._metadata.size : 0) - (y._metadata ? y._metadata.size : 0));
+        return ((x._metadata ? x._metadata.size : 0) - (y._metadata ? y._metadata.size : 0));
     }
 
     function modificationTimeCompare(x, y)
     {
-        return reverseFactor * ((x._metadata ? x._metadata.modificationTime : 0) - (y._metadata ? y._metadata.modificationTime : 0));
+        return ((x._metadata ? x._metadata.modificationTime : 0) - (y._metadata ? y._metadata.modificationTime : 0));
     }
 }
 
 WebInspector.DirectoryContentView.Node.prototype = {
     /**
      * @param {number} errorCode
      * @param {!FileSystemAgent.Metadata} metadata
      */
     _metadataReceived: function(errorCode, metadata)
     {
         const indexes = WebInspector.DirectoryContentView.columnIndexes;
         if (errorCode !== 0)
             return;
 
         this._metadata = metadata;
         var data = this.data;
         if (this._entry.isDirectory)
             data[indexes.Size] = WebInspector.UIString("-");
         else
             data[indexes.Size] = Number.bytesToString(metadata.size);
         data[indexes.ModificationTime] = new Date(metadata.modificationTime).toISOString();
         this.data = data;
     },
 
     __proto__: WebInspector.DataGridNode.prototype
 }