DevTools: Implement recursive viewport for the Heap Summary view

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

 var initialize_HeapSnapshotTest = function() {
 
 InspectorTest.createHeapSnapshotMockFactories = function() {
 
 InspectorTest.createJSHeapSnapshotMockObject = function()
 {
     return {
         _rootNodeIndex: 0,
         _nodeTypeOffset: 0,
         _nodeNameOffset: 1,
@@ skipping 671 matching lines @@
             return node;
     }
     return null;
 };
 
 InspectorTest.switchToView = function(title, callback)
 {
     callback = InspectorTest.safeWrap(callback);
     var view = WebInspector.panels.profiles.visibleView;
     view.changeView(title, callback);
+    // Increase the grid container height so the viewport don't limit the number of nodes.
+    InspectorTest._currentGrid().scrollContainer.style.height = "10000px";
 };
 
 InspectorTest.takeAndOpenSnapshot = function(generator, callback)
 {
     callback = InspectorTest.safeWrap(callback);
     var snapshot = generator();
     var profileType =  WebInspector.ProfileTypeRegistry.instance.heapSnapshotProfileType;
     function pushGeneratedSnapshot(reportProgress, callback)
     {
         var profile = profileType.profileBeingRecorded();
@@ skipping 34 matching lines @@
         function sortingComplete()
         {
             dataGrid.removeEventListener("sorting complete", sortingComplete, null);
             callback();
         }
         dataGrid.addEventListener("sorting complete", sortingComplete, null);
     }
 };
 
 };