[DevTools] Add grow mode to ListControl.

third_party/WebKit/LayoutTests/http/tests/inspector-unit/list-control-variable-height.js

 TestRunner.addResult('Test ListControl rendering for variable height case.');
 
 class Delegate {
   constructor() {
   }
 
   createElementForItem(item) {
     TestRunner.addResult('Creating element for ' + item);
     var element = document.createElement('div');
     element.style.height = this.heightForItem(item) + 'px';
@@ skipping 12 matching lines @@
   selectedItemChanged(from, to, fromElement, toElement) {
     TestRunner.addResult('Selection changed from ' + from + ' to ' + to);
     if (fromElement)
       fromElement.classList.remove('selected');
     if (toElement)
       toElement.classList.add('selected');
   }
 }
 
 var delegate = new Delegate();
-var list = new UI.ListControl(delegate);
-list.setHeightMode(UI.ListHeightMode.Variable);
+var list = new UI.ListControl(delegate, UI.ListMode.ViewportVariableItems);
 list.element.style.height = '73px';
 UI.inspectorView.element.appendChild(list.element);
 
 function dumpList()
 {
   var height = list.element.offsetHeight;
   TestRunner.addResult(`----list[length=${list.length()}][height=${height}]----`);
   for (var child of list.element.children) {
     var offsetTop = child.getBoundingClientRect().top - list.element.getBoundingClientRect().top;
     var offsetBottom = child.getBoundingClientRect().bottom - list.element.getBoundingClientRect().top;
@@ skipping 62 matching lines @@
 TestRunner.addResult('Replacing 45 with 16-18');
 list.replaceItemsInRange(16, 17, [16, 17, 18]);
 dumpList();
 
 TestRunner.addResult('Resizing');
 list.element.style.height = '190px';
 list.viewportResized();
 dumpList();
 
 TestRunner.completeTest();