Revert of [Devtools] Moved flatten children to children nodes instead of datagrid

third_party/WebKit/LayoutTests/inspector/components/viewport-datagrid.html

Index: third_party/WebKit/LayoutTests/inspector/components/viewport-datagrid.html
diff --git a/third_party/WebKit/LayoutTests/inspector/components/viewport-datagrid.html b/third_party/WebKit/LayoutTests/inspector/components/viewport-datagrid.html
index e53225e10dbec381b7fb57036dcfce0b7bd69e24..d31110b28a116261f5e116acc50684b9851def94 100644
--- a/third_party/WebKit/LayoutTests/inspector/components/viewport-datagrid.html
+++ b/third_party/WebKit/LayoutTests/inspector/components/viewport-datagrid.html
@@ -42,16 +42,6 @@
         InspectorTest.addResult("Collapsed node " + node.data.id);
     }
 
-    function dumpFlattenChildren()
-    {
-        var nodes = dataGrid.rootNode().flattenChildren();
-        InspectorTest.addResult("Checking flattenChildren():");
-        for (var node of nodes) {
-            InspectorTest.addResult("  " + node.data.id);
-        }
-        InspectorTest.addResult("");
-    }
-
     var columns = [{id: "id", title: "ID column", width: "250px"}];
     var dataGrid = new UI.ViewportDataGrid(columns);
     var a = new UI.ViewportDataGridNode({id: "a"});
@@ -84,12 +74,8 @@
 
     // Appending to tree.
     attach(root, a);
-    // a is collapsed.
     attach(a, aa);
-    expand(a);
-    dumpFlattenChildren();
     attach(a, ab);
-    dumpFlattenChildren();
     attach(root, b);
 
     dumpNodes();
@@ -121,16 +107,11 @@
     dumpNodes();
     attach(ab, aac);
     aac.revealAndSelect();
-    dumpFlattenChildren();
-    InspectorTest.addResult("Removed children of aa");
     aa.removeChildren();
-    dumpFlattenChildren();
     dumpNodes();
     attach(ab, aac);
     aac.revealAndSelect();
-    dumpFlattenChildren();
     detach(a, aa);
-    dumpFlattenChildren();
     dumpNodes();
     detach(a, ab);
     dumpNodes();