Revert "[vm] Don't enable the profiler by default. Enable the profiler at startup with --observe, o…

runtime/observatory/lib/src/elements/cpu_profile/virtual_tree.dart

Index: runtime/observatory/lib/src/elements/cpu_profile/virtual_tree.dart
diff --git a/runtime/observatory/lib/src/elements/cpu_profile/virtual_tree.dart b/runtime/observatory/lib/src/elements/cpu_profile/virtual_tree.dart
index 21c4388bc43674df1d842e5c3f4d92a2d8625f61..77e1a724f7f84056aa895f76af2c7c440a108f52 100644
--- a/runtime/observatory/lib/src/elements/cpu_profile/virtual_tree.dart
+++ b/runtime/observatory/lib/src/elements/cpu_profile/virtual_tree.dart
@@ -128,14 +128,7 @@ class CpuProfileVirtualTreeElement extends HtmlElement implements Renderable {
     }
     _tree = new VirtualTreeElement(create, update, _getChildren,
         items: tree.root.children, queue: _r.queue);
-    if (tree.root.children.length == 0) {
-      children = [
-        new DivElement()
-          ..classes = ['tree-item']
-          ..children = [new HeadingElement.h1()..text = 'No Samples']
-      ];
-      return;
-    } else if (tree.root.children.length == 1) {
+    if (tree.root.children.length == 1) {
       _tree.expand(tree.root.children.first, autoExpandSingleChildNodes: true);
     }
     children = [_tree];