Use std::default_delete as the default deleter for scoped_ptr.

crypto/scoped_nss_types.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.
 
 #ifndef CRYPTO_SCOPED_NSS_TYPES_H_
 #define CRYPTO_SCOPED_NSS_TYPES_H_
 
 #include <keyhi.h>
 #include <nss.h>
 #include <pk11pub.h>
 #include <plarena.h>
 
 #include "base/memory/scoped_ptr.h"
 
 namespace crypto {
 
 template <typename Type, void (*Destroyer)(Type*)>
 struct NSSDestroyer {
-  typedef void AllowSelfReset;

[danakj, 2015/11/17 19:09:27]

Can you maybe replace each of these AllowSelfReset with a comment saying that
this destroyer was written in a way that will allow self reset?

[dcheng, 2015/11/17 20:21:03]

Hmm... that's not really immediately obvious that comment would be true though
(as it depends on the actual Destroyer implementation), right? TBH, looking at
the CL that introduced this, I'm not even sure why it was needed in the end:
https://codereview.chromium.org/610533003

+davidben, is this something you'd find valuable?

[davidben, 2015/11/17 21:01:45]

Part of this change is to remove the self-reset check in scoped_ptr altogether,
right? If so, then there's probably no need to keep a mention around as scar
tissue. So this lgtm.

(Self-reset was needed with the old scoped_ptr behavior because NSS and OpenSSL
types are all intrusively reference-counted. And so two ScopedFOO might contain
the same FOO* pointer by value, but each owns its own reference to it.)

   void operator()(Type* ptr) const {
     Destroyer(ptr);
   }
 };
 
 template <typename Type, void (*Destroyer)(Type*, PRBool), PRBool freeit>
 struct NSSDestroyer1 {
-  typedef void AllowSelfReset;
   void operator()(Type* ptr) const {
     Destroyer(ptr, freeit);
   }
 };
 
 // Define some convenient scopers around NSS pointers.
 typedef scoped_ptr<PK11Context,
                    NSSDestroyer1<PK11Context, PK11_DestroyContext, PR_TRUE> >
     ScopedPK11Context;
 typedef scoped_ptr<PK11SlotInfo, NSSDestroyer<PK11SlotInfo, PK11_FreeSlot> >
@@ skipping 14 matching lines @@
     ScopedSECAlgorithmID;
 typedef scoped_ptr<SECItem, NSSDestroyer1<SECItem, SECITEM_FreeItem, PR_TRUE> >
     ScopedSECItem;
 typedef scoped_ptr<PLArenaPool,
                    NSSDestroyer1<PLArenaPool, PORT_FreeArena, PR_FALSE> >
     ScopedPLArenaPool;
 
 }  // namespace crypto
 
 #endif  // CRYPTO_SCOPED_NSS_TYPES_H_