Delete PNaCl translation cache backend object when no longer needed

chrome/browser/nacl_host/pnacl_translation_cache.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_TRANSLATION_CACHE_H_
 #define CHROME_BROWSER_NACL_HOST_PNACL_TRANSLATION_CACHE_H_
 
 #include <map>
 
 #include "base/callback.h"
@@ skipping 24 matching lines @@
     GetNexeCallback;
 class PnaclTranslationCacheEntry;
 extern const int kMaxMemCacheSize;
 
 class PnaclTranslationCache
     : public base::SupportsWeakPtr<PnaclTranslationCache> {
  public:
   PnaclTranslationCache();
   virtual ~PnaclTranslationCache();
 
-  // Initialize the translation cache in |cache_dir|.
-  // Call |callback| with a 0 argument on sucess and <0 otherwise.
+  // Initialize the translation cache in |cache_dir|.  If the return value is
+  // net::ERR_IO_PENDING, |callback| will be called with a 0 argument on sucess
+  // and <0 otherwise.
   int InitOnDisk(const base::FilePath& cache_dir,
                  const CompletionCallback& callback);
 
-  // Initialize the translation cache in memory.
-  // Call |callback| with a 0 argument on sucess and <0 otherwise.
+  // Initialize the translation cache in memory.  If the return value is
+  // net::ERR_IO_PENDING, |callback| will be called with a 0 argument on sucess
+  // and <0 otherwise.
   int InitInMemory(const CompletionCallback& callback);
 
-  // Store the nexe in the translation cache. A reference to |nexe_data| is
-  // held until completion or cancellation.
-  void StoreNexe(const std::string& key, net::DrainableIOBuffer* nexe_data);
-
   // Store the nexe in the translation cache, and call |callback| with
   // the result. The result passed to the callback is 0 on success and
   // <0 otherwise. A reference to |nexe_data| is held until completion
   // or cancellation.
   void StoreNexe(const std::string& key,
                  net::DrainableIOBuffer* nexe_data,
                  const CompletionCallback& callback);
 
   // Retrieve the nexe from the translation cache. Write the data into |nexe|
   // and call |callback|, passing a result code (0 on success and <0 otherwise),
@@ skipping 31 matching lines @@
   CompletionCallback init_callback_;
   bool in_memory_;
   std::map<void*, scoped_refptr<PnaclTranslationCacheEntry> > open_entries_;
 
   DISALLOW_COPY_AND_ASSIGN(PnaclTranslationCache);
 };
 
 }  // namespace pnacl
 
 #endif  // CHROME_BROWSER_NACL_HOST_PNACL_TRANSLATION_CACHE_H_