[net] Change factory methods for HostResolver and HostCache to return a scoped_ptr

net/base/host_cache.cc

 // 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.
 
 #include "net/base/host_cache.h"
 
 #include "base/logging.h"
 #include "net/base/net_errors.h"
 
 namespace net {
@@ skipping 53 matching lines @@
   return entries_.max_entries();
 }
 
 // Note that this map may contain expired entries.
 const HostCache::EntryMap& HostCache::entries() const {
   DCHECK(CalledOnValidThread());
   return entries_;
 }
 
 // static
-HostCache* HostCache::CreateDefaultCache() {
+scoped_ptr<HostCache> HostCache::CreateDefaultCache() {
   static const size_t kMaxHostCacheEntries = 100;
-  return new HostCache(kMaxHostCacheEntries);
+  return make_scoped_ptr(new HostCache(kMaxHostCacheEntries));
 }
 
 }  // namespace net