perf(benchmarks): update ng2-switch to match ng2

- use the ~same template layout (text nodes),
- use trackBy

both benchmark now show about the same perfs.

modules/benchmarks/src/largetable/ng2/table.ts

@@ -5,8 +5,13 @@ import {TableCell, emptyTable} from '../util';
 
 @Component({
   selector: 'largetable',
-  template:
-      `<table><tbody><tr *ngFor="let row of data; trackBy: trackByIndex"><td *ngFor="let cell of row; trackBy: trackByIndex" [style.backgroundColor]="cell.row % 2 ? '' : 'grey'">{{cell.value}}</td></tr></tbody></table>`
+  template: `<table><tbody>
+    <tr *ngFor="let row of data; trackBy: trackByIndex">
+      <td *ngFor="let cell of row; trackBy: trackByIndex" [style.backgroundColor]="cell.row % 2 ? '' : 'grey'">
+      {{cell.value}}
+      </td>
+    </tr>
+  </tbody></table>`,
 })
 export class TableComponent {
   @Input()

modules/benchmarks/src/largetable/ng2_switch/table.ts

@@ -6,18 +6,18 @@ import {TableCell, emptyTable} from '../util';
 @Component({
   selector: 'largetable',
   template: `<table><tbody>
-    <tr *ngFor="let row of data">
-    <template ngFor [ngForOf]="row" let-cell>
-      <ng-container [ngSwitch]="cell.row % 2">
-        <td *ngSwitchCase="0" style="background-color: grey">{{cell.value}}</td>
-        <td *ngSwitchDefault>{{cell.value}}</td>
-      </ng-container>
-    </template>
-    </tr></tbody></table>`
+    <tr *ngFor="let row of data; trackBy: trackByIndex">
+    <template ngFor [ngForOf]="row" [ngForTrackBy]="trackByIndex" let-cell><ng-container [ngSwitch]="cell.row % 2">
+        <td *ngSwitchCase="0" style="background-color: grey">{{cell.value}}</td><td *ngSwitchDefault>{{cell.value}}</td>    
+    </ng-container></template>
+    </tr>
+  </tbody></table>`
 })
 export class TableComponent {
   @Input()
   data: TableCell[][] = emptyTable;
+
+  trackByIndex(index: number, item: any) { return index; }
 }
 
 @NgModule({imports: [BrowserModule], bootstrap: [TableComponent], declarations: [TableComponent]})