Remove unneeded uses of base/ref_counted.h.

base/waitable_event.h

 // Copyright (c) 2006-2008 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.
 
 #ifndef BASE_WAITABLE_EVENT_H_
 #define BASE_WAITABLE_EVENT_H_
 
 #include "base/basictypes.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #endif
 
 #if defined(OS_POSIX)
 #include <list>
 #include <utility>
 #include "base/condition_variable.h"
 #include "base/lock.h"
-#include "base/ref_counted.h"
 #endif
 
 #include "base/message_loop.h"
 
 namespace base {
 
 // This replaces INFINITE from Win32
 static const int kNoTimeout = -1;
 
 class TimeDelta;
@@ skipping 120 matching lines @@
   const bool manual_reset_;
   std::list<Waiter*> waiters_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(WaitableEvent);
 };
 
 }  // namespace base
 
 #endif  // BASE_WAITABLE_EVENT_H_