Delete PNaCl translation cache backend object when no longer needed

chrome/browser/nacl_host/pnacl_translation_cache.cc

Index: chrome/browser/nacl_host/pnacl_translation_cache.cc
diff --git a/chrome/browser/nacl_host/pnacl_translation_cache.cc b/chrome/browser/nacl_host/pnacl_translation_cache.cc
index e3c8c207cbb429c29bd1b40e2d6a2dd62fee2922..56354792ebb6bf4ffe854927401c8781a44ceac4 100644
--- a/chrome/browser/nacl_host/pnacl_translation_cache.cc
+++ b/chrome/browser/nacl_host/pnacl_translation_cache.cc
@@ -6,6 +6,7 @@
 
 #include <string>
 
+#include "base/callback.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
@@ -67,7 +68,8 @@ class PnaclTranslationCacheEntry
     OPEN_ENTRY,
     CREATE_ENTRY,
     TRANSFER_ENTRY,
-    CLOSE_ENTRY
+    CLOSE_ENTRY,
+    FINISHED
   };
 
  private:
@@ -142,8 +144,21 @@ PnaclTranslationCacheEntry::PnaclTranslationCacheEntry(
 
 PnaclTranslationCacheEntry::~PnaclTranslationCacheEntry() {
   // Ensure we have called the user's callback
-  DCHECK(read_callback_.is_null());
-  DCHECK(write_callback_.is_null());
+  if (step_ != FINISHED) {
+    if (!read_callback_.is_null()) {
+      BrowserThread::PostTask(
+          BrowserThread::IO,
+          FROM_HERE,
+          base::Bind(read_callback_,
+                     net::ERR_ABORTED,
+                     scoped_refptr<net::DrainableIOBuffer>()));
+    }
+    if (!write_callback_.is_null()) {
+      BrowserThread::PostTask(BrowserThread::IO,
+                              FROM_HERE,
+                              base::Bind(write_callback_, net::ERR_ABORTED));
+    }
+  }
 }
 
 void PnaclTranslationCacheEntry::Start() {
@@ -208,15 +223,17 @@ void PnaclTranslationCacheEntry::CloseEntry(int rv) {
 }
 
 void PnaclTranslationCacheEntry::Finish(int rv) {
+  step_ = FINISHED;
   if (is_read_) {
     if (!read_callback_.is_null()) {
-      read_callback_.Run(rv, io_buf_);
-      read_callback_.Reset();
+      BrowserThread::PostTask(BrowserThread::IO,
+                              FROM_HERE,
+                              base::Bind(read_callback_, rv, io_buf_));
     }
   } else {
     if (!write_callback_.is_null()) {
-      write_callback_.Run(rv);
-      write_callback_.Reset();
+      BrowserThread::PostTask(
+          BrowserThread::IO, FROM_HERE, base::Bind(write_callback_, rv));
     }
   }
   cache_->OpComplete(this);
@@ -229,6 +246,7 @@ void PnaclTranslationCacheEntry::DispatchNext(int rv) {
 
   switch (step_) {
     case UNINITIALIZED:
+    case FINISHED:
       LOG(ERROR) << "DispatchNext called uninitialized";
       break;
 
@@ -273,8 +291,8 @@ void PnaclTranslationCacheEntry::DispatchNext(int rv) {
       if (rv < 0) {
         // We do not call DispatchNext directly if WriteEntry/ReadEntry returns
         // ERR_IO_PENDING, and the callback should not return that value either.
-        LOG(ERROR)
-            << "Failed to complete write to entry: " << net::ErrorToString(rv);
+        LOG(ERROR) << "Failed to complete write to entry: "
+                   << net::ErrorToString(rv);
         step_ = CLOSE_ENTRY;
         CloseEntry(rv);
         break;
@@ -326,9 +344,8 @@ int PnaclTranslationCache::Init(net::CacheType cache_type,
       NULL, /* dummy net log */
       &disk_cache_,
       base::Bind(&PnaclTranslationCache::OnCreateBackendComplete, AsWeakPtr()));
-  init_callback_ = callback;
-  if (rv != net::ERR_IO_PENDING) {
-    OnCreateBackendComplete(rv);
+  if (rv == net::ERR_IO_PENDING) {
+    init_callback_ = callback;
   }
   return rv;
 }
@@ -339,8 +356,8 @@ void PnaclTranslationCache::OnCreateBackendComplete(int rv) {
   }
   // Invoke our client's callback function.
   if (!init_callback_.is_null()) {
-    init_callback_.Run(rv);
-    init_callback_.Reset();
+    BrowserThread::PostTask(
+        BrowserThread::IO, FROM_HERE, base::Bind(init_callback_, rv));
   }
 }
 
@@ -348,11 +365,6 @@ void PnaclTranslationCache::OnCreateBackendComplete(int rv) {
 // High-level API
 
 void PnaclTranslationCache::StoreNexe(const std::string& key,
-                                      net::DrainableIOBuffer* nexe_data) {
-  StoreNexe(key, nexe_data, CompletionCallback());
-}
-
-void PnaclTranslationCache::StoreNexe(const std::string& key,
                                       net::DrainableIOBuffer* nexe_data,
                                       const CompletionCallback& callback) {
   PnaclTranslationCacheEntry* entry = PnaclTranslationCacheEntry::GetWriteEntry(