Change the API of disk_cache::CreateCacheBackend to use scoped_ptr

net/http/http_cache.h

 // Copyright (c) 2012 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.
 
 // This file declares a HttpTransactionFactory implementation that can be
 // layered on top of another HttpTransactionFactory to add HTTP caching.  The
 // caching logic follows RFC 2616 (any exceptions are called out in the code).
 //
 // The HttpCache takes a disk_cache::Backend as a parameter, and uses that for
 // the cache storage.
@@ skipping 71 matching lines @@
    public:
     virtual ~BackendFactory() {}
 
     // The actual method to build the backend. Returns a net error code. If
     // ERR_IO_PENDING is returned, the |callback| will be notified when the
     // operation completes, and |backend| must remain valid until the
     // notification arrives.
     // The implementation must not access the factory object after invoking the
     // |callback| because the object can be deleted from within the callback.
     virtual int CreateBackend(NetLog* net_log,
-                              disk_cache::Backend** backend,
+                              scoped_ptr<disk_cache::Backend>* backend,
                               const CompletionCallback& callback) = 0;
   };
 
   // A default backend factory for the common use cases.
   class NET_EXPORT DefaultBackend : public BackendFactory {
    public:
     // |path| is the destination for any files used by the backend, and
     // |cache_thread| is the thread where disk operations should take place. If
     // |max_bytes| is  zero, a default value will be calculated automatically.
     DefaultBackend(CacheType type, BackendType backend_type,
                    const base::FilePath& path, int max_bytes,
                    base::MessageLoopProxy* thread);
     virtual ~DefaultBackend();
 
     // Returns a factory for an in-memory cache.
     static BackendFactory* InMemory(int max_bytes);
 
     // BackendFactory implementation.
     virtual int CreateBackend(NetLog* net_log,
-                              disk_cache::Backend** backend,
+                              scoped_ptr<disk_cache::Backend>* backend,
                               const CompletionCallback& callback) OVERRIDE;
 
    private:
     CacheType type_;
     BackendType backend_type_;
     const base::FilePath path_;
     int max_bytes_;
     scoped_refptr<base::MessageLoopProxy> thread_;
   };
 
@@ skipping 272 matching lines @@
   PendingOpsMap pending_ops_;
 
   scoped_ptr<PlaybackCacheMap> playback_cache_map_;
 
   DISALLOW_COPY_AND_ASSIGN(HttpCache);
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_CACHE_H_