Implement view port for allocation view

Source/devtools/front_end/HeapSnapshotDataGrids.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 1036 matching lines @@
 
         this.snapshot.dominatorIdsForNode(parseInt(id, 10), didGetDominators.bind(this));
     },
 
     __proto__: WebInspector.HeapSnapshotSortableDataGrid.prototype
 }
 
 
 /**
  * @constructor
- * @extends {WebInspector.DataGrid}
+ * @extends {WebInspector.HeapSnapshotViewportDataGrid}
  */
 WebInspector.AllocationDataGrid = function()
 {
     var columns = [
         {id: "liveCount", title: WebInspector.UIString("Live Count"), width: "72px", sortable: true},
         {id: "count", title: WebInspector.UIString("Count"), width: "72px", sortable: true},
         {id: "liveSize", title: WebInspector.UIString("Live Size"), width: "72px", sortable: true},
         {id: "size", title: WebInspector.UIString("Size"), width: "72px", sortable: true, sort: WebInspector.DataGrid.Order.Descending},
         {id: "name", title: WebInspector.UIString("Function"), disclosure: true, sortable: true},
     ];
-    WebInspector.DataGrid.call(this, columns);
+    WebInspector.HeapSnapshotViewportDataGrid.call(this, columns);
     this._linkifier = new WebInspector.Linkifier();
-    this.addEventListener(WebInspector.DataGrid.Events.SortingChanged, this._sortingChanged, this);
 }
 
 WebInspector.AllocationDataGrid.prototype = {
     setDataSource: function(snapshot)
     {
         this.snapshot = snapshot;
         this.snapshot.allocationTracesTops(didReceiveAllocationTracesTops.bind(this));
 
         /**
          * @param {!Array.<!WebInspector.HeapSnapshotCommon.SerializedAllocationNode>} tops
          * @this {WebInspector.AllocationDataGrid}
          */
         function didReceiveAllocationTracesTops(tops)
         {
             this._topNodes = tops;
             this._populateChildren();
         }
     },
 
     _populateChildren: function()
     {
+        this.removeTopLevelNodes();
         var root = this.rootNode();
         var tops = this._topNodes;
         for (var i = 0; i < tops.length; i++)
-            root.appendChild(new WebInspector.AllocationGridNode(this, tops[i]));
+            this.appendNode(root, new WebInspector.AllocationGridNode(this, tops[i]));
+        this.updateVisibleNodes(true);
     },
 
-    _sortingChanged: function()
+    sortingChanged: function()
     {
         this._topNodes.sort(this._createComparator());
         this.rootNode().removeChildren();
         this._populateChildren();
     },
 
 
     /**
      * @return {function(!Object, !Object):number}
      */
@@ skipping 10 matching lines @@
         {
             if (a[fieldName] > b[fieldName])
                 return compareResult;
             if (a[fieldName] < b[fieldName])
                 return -compareResult;
             return 0;
         }
         return compare;
      },
 
-    __proto__: WebInspector.DataGrid.prototype
+    __proto__: WebInspector.HeapSnapshotViewportDataGrid.prototype
 }