Clear disk cache when the cache is not initialized

chrome/browser/browsing_data_remover.cc

 // Copyright (c) 2006-2008 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.
 
 #include "chrome/browser/browsing_data_remover.h"
 
 #include "chrome/browser/chrome_thread.h"
 #include "chrome/browser/download/download_manager.h"
 #include "chrome/browser/history/history.h"
 #include "chrome/browser/profile.h"
@@ skipping 222 matching lines @@
     URLRequestContextGetter* main_context_getter,
     URLRequestContextGetter* media_context_getter,
     base::Time delete_begin,
     base::Time delete_end) {
   // This function should be called on the IO thread.
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::IO));
 
   // Get a pointer to the cache.
   net::HttpTransactionFactory* factory =
       main_context_getter->GetURLRequestContext()->http_transaction_factory();
-  disk_cache::Backend* cache = factory->GetCache()->disk_cache();
+  disk_cache::Backend* cache = factory->GetCache()->GetBackend();
 
-  // |cache| can be null since it is lazily initialized, in this case we do
-  // nothing.
+  // |cache| can be null if it cannot be initialized.
   if (cache) {
     if (delete_begin.is_null())
       cache->DoomAllEntries();
     else
       cache->DoomEntriesBetween(delete_begin, delete_end);
   }
 
   // Get a pointer to the media cache.
   factory = media_context_getter->GetURLRequestContext()->
       http_transaction_factory();
-  cache = factory->GetCache()->disk_cache();
+  cache = factory->GetCache()->GetBackend();
 
-  // |cache| can be null since it is lazily initialized, in this case we do
-  // nothing.
+  // |cache| can be null if it cannot be initialized.
   if (cache) {
     if (delete_begin.is_null())
       cache->DoomAllEntries();
     else
       cache->DoomEntriesBetween(delete_begin, delete_end);
   }
 
   // Balance the AddRef()s done on the UI thread by Remove().
   main_context_getter->Release();
   media_context_getter->Release();
 
   // Notify the UI thread that we are done.
   ChromeThread::PostTask(
       ChromeThread::UI, FROM_HERE,
       NewRunnableMethod(this, &BrowsingDataRemover::ClearedCache));
 }