Delete PNaCl translation cache backend object when no longer needed

chrome/browser/nacl_host/pnacl_translation_cache.h

Index: chrome/browser/nacl_host/pnacl_translation_cache.h
diff --git a/chrome/browser/nacl_host/pnacl_translation_cache.h b/chrome/browser/nacl_host/pnacl_translation_cache.h
index 2baa53aba3d067f5637d8fa371d8fca68192a244..7ca4bcc65ca26103baa4a33c7d69ede552ebb2c9 100644
--- a/chrome/browser/nacl_host/pnacl_translation_cache.h
+++ b/chrome/browser/nacl_host/pnacl_translation_cache.h
@@ -42,19 +42,17 @@ class PnaclTranslationCache
   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