Revert 144488 - For unit tests, track additions to AtExitManager and warn.

base/at_exit.h

Index: base/at_exit.h
===================================================================
--- base/at_exit.h	(revision 148403)
+++ base/at_exit.h	(working copy)
@@ -1,4 +1,4 @@
-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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.
 
@@ -14,8 +14,6 @@
 
 namespace base {
 
-class TestWatchAtExitManager;
-
 // This class provides a facility similar to the CRT atexit(), except that
 // we control when the callbacks are executed. Under Windows for a DLL they
 // happen at a really bad time and under the loader lock. This facility is
@@ -59,11 +57,6 @@
   explicit AtExitManager(bool shadow);
 
  private:
-  friend class TestWatchAtExitManager;
-
-  static AtExitManager* current();
-  size_t CallbackStackSize() const;
-
   base::Lock lock_;
   std::stack<base::Closure> stack_;
   AtExitManager* next_manager_;  // Stack of managers to allow shadowing.