Fix tsan failure

runtime/observatory/tests/service/get_allocation_samples_test.dart

Index: runtime/observatory/tests/service/get_allocation_samples_test.dart
diff --git a/runtime/observatory/tests/service/get_allocation_samples_test.dart b/runtime/observatory/tests/service/get_allocation_samples_test.dart
index d26c75f4d135085bf15af323eb27cf30e51924c4..bf4e1990a2da3c36ed50d884533d81c130ceba2a 100644
--- a/runtime/observatory/tests/service/get_allocation_samples_test.dart
+++ b/runtime/observatory/tests/service/get_allocation_samples_test.dart
@@ -67,8 +67,8 @@ var tests = [
     cpuProfile.buildFunctionCallerAndCallees();
     var tree = cpuProfile.loadCodeTree(M.ProfileTreeDirection.exclusive);
     var node = tree.root;
-    var expected =
-        ['Root', 'DRT_AllocateObject', 'test', 'test', '_Closure.call'];
+    var expected = ['Root', 'DRT_AllocateObject', '[Stub] Allocate Foo',
+                    'test', 'test', '_Closure.call'];
     for (var i = 0; i < expected.length; i++) {
       expect(node.profileCode.code.name, equals(expected[i]));
       // Depth first traversal.