[Devtools] Cleanup DataGrid's typecast and identifier naming

third_party/WebKit/LayoutTests/inspector/profiler/heap-snapshot-test.js

 var initialize_HeapSnapshotTest = function() {
 
 InspectorTest.preloadPanel("profiles");
 
 InspectorTest.createHeapSnapshotMockFactories = function() {
 
 InspectorTest.createJSHeapSnapshotMockObject = function()
 {
     return {
         _rootNodeIndex: 0,
@@ skipping 502 matching lines @@
         var result = simpleComparator(a, b);
         if (result !== 0 && result !== acceptableComparisonResult) {
             InspectorTest.addResult("Elements " + i + " and " + (i + 1) + " are out of order: " + a + " " + b + " (" + sortOrder + ")");
         }
     }
 };
 
 InspectorTest.clickColumn = function(column, callback)
 {
     callback = InspectorTest.safeWrap(callback);
-    var cell = this._currentGrid()._headerTableHeaders[column.identifier];
+    var cell = this._currentGrid()._headerTableHeaders[column.id];
     var event = { target: { enclosingNodeOrSelfWithNodeName: function() { return cell; } } };
 
     function sortingComplete()
     {
         InspectorTest._currentGrid().removeEventListener(WebInspector.HeapSnapshotSortableDataGrid.Events.SortingComplete, sortingComplete, this);
-        InspectorTest.assertEquals(column.identifier, this._currentGrid().sortColumnIdentifier(), "unexpected sorting");
+        InspectorTest.assertEquals(column.id, this._currentGrid().sortColumnId(), "unexpected sorting");
         column.sort = this._currentGrid().sortOrder();
         function callCallback()
         {
             callback(column);
         }
         setTimeout(callCallback, 0);
     }
     InspectorTest._currentGrid().addEventListener(WebInspector.HeapSnapshotSortableDataGrid.Events.SortingComplete, sortingComplete, this);
     this._currentGrid()._clickInHeaderCell(event);
 };
@@ skipping 187 matching lines @@
         function sortingComplete()
         {
             dataGrid.removeEventListener(WebInspector.HeapSnapshotSortableDataGrid.Events.SortingComplete, sortingComplete, null);
             callback();
         }
         dataGrid.addEventListener(WebInspector.HeapSnapshotSortableDataGrid.Events.SortingComplete, sortingComplete, null);
     }
 };
 
 };