Delete PNaCl translation cache backend object when no longer needed

chrome/browser/nacl_host/pnacl_host.h

 // Copyright 2013 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 CHROME_BROWSER_NACL_HOST_PNACL_HOST_H_
 #define CHROME_BROWSER_NACL_HOST_PNACL_HOST_H_
 
 #include <map>
 
 #include "base/callback_forward.h"
@@ skipping 139 matching lines @@
   void StoreTranslatedNexe(TranslationID id,
                            scoped_refptr<net::DrainableIOBuffer>);
   void OnTranslatedNexeStored(const TranslationID& id, int net_error);
   void RequeryMatchingTranslations(const std::string& key);
 
   // GetNexeFd hit path
   static int CopyBufferToFile(base::PlatformFile fd,
                               scoped_refptr<net::DrainableIOBuffer> buffer);
   void OnBufferCopiedToTempFile(const TranslationID& id, int file_error);
 
-  static void OnEntriesDoomed(const base::Closure& callback, int net_error);
+  void OnEntriesDoomed(const base::Closure& callback, int net_error);
 
+  void DeInitIfSafe();
+
+  // Operations which are pending with the cache backend, which we should
+  // wait for before destroying it (see comment on DeInitIfSafe).
+  int pending_backend_operations_;
   CacheState cache_state_;
   base::FilePath temp_dir_;
   scoped_ptr<pnacl::PnaclTranslationCache> disk_cache_;
   PendingTranslationMap pending_translations_;
   base::ThreadChecker thread_checker_;
   base::WeakPtrFactory<PnaclHost> weak_factory_;
   DISALLOW_COPY_AND_ASSIGN(PnaclHost);
 };
 
 #endif  // CHROME_BROWSER_NACL_HOST_PNACL_HOST_H_