For unit tests, track additions to AtExitManager and warn.

base/test/unit_test.cc

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/test/unit_test.h"
+
+#include "base/at_exit.h"
+#include "base/logging.h"
+
+namespace base {
+
+UnitTest::UnitTest() {
+}
+
+UnitTest::~UnitTest() {
+}
+
+void UnitTest::SetUp() {
+  base::ShadowingAtExitManager at_exit_manager;
+  initial_top_manager_ = at_exit_manager.next_manager_;
+  at_exit_stack_size_ = initial_top_manager_->stack_.size();
+}
+
+void UnitTest::TearDown() {
+  base::ShadowingAtExitManager at_exit_manager;
+  base::AtExitManager* new_top_manager = at_exit_manager.next_manager_;
+  size_t new_stack_size = new_top_manager->stack_.size();
+
+  if (initial_top_manager_ != new_top_manager) {
+    LOG(WARNING) << "AtExitManager stack changed depth across test.";
+  } else if (new_stack_size != at_exit_stack_size_) {
+    LOG(WARNING) << "Test added items to the AtExitManager list.";
+  }
+}
+
+}  // namespace base