[NaCl SDK] Get nacl_mounts_tests building.

native_client_sdk/src/libraries/utils/ref_object.h

 /* 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.
  */
 
 #ifndef LIBRARIES_UTILS_REF_OBJECT
 #define LIBRARIES_UTILS_REF_OBJECT
 
 #include <stdlib.h>
 #include "pthread.h"
 
 class RefObject {
  public:
   RefObject() {
     ref_count_ = 1;
     pthread_mutex_init(&lock_, NULL);
   }
 
   int RefCount() const { return ref_count_; }
 
   void Acquire() {
     ref_count_++;
   }
-  void Release() {
+  bool Release() {
     if (--ref_count_ == 0) {
       delete this;
+      return false;
     }
+    return true;
   }
 
  protected:
   virtual ~RefObject() {
     pthread_mutex_destroy(&lock_);
   }
 
   pthread_mutex_t lock_;
 
  private:
   int ref_count_;
 };
 
 #endif  // LIBRARIES_UTILS_REF_OBJECT