snapshot: Make destructors of interface classes public and virtual

snapshot/mac/memory_snapshot_mac.h

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 13 matching lines @@
 #include "util/misc/initialization_state_dcheck.h"
 
 namespace crashpad {
 namespace internal {
 
 //! \brief A MemorySnapshot of a memory region in a process on the running
 //!     system, when the system runs Mac OS X.
 class MemorySnapshotMac final : public MemorySnapshot {
  public:
   MemorySnapshotMac();
-  ~MemorySnapshotMac();
+  ~MemorySnapshotMac() override;
 
   //! \brief Initializes the object.
   //!
   //! Memory is read lazily. No attempt is made to read the memory snapshot data
   //! until Read() is called, and the memory snapshot data is discared when
   //! Read() returns.
   //!
   //! \param[in] process_reader A reader for the process being snapshotted.
   //! \param[in] address The base address of the memory region to snapshot, in
   //!     the snapshot process’ address space.
@@ skipping 14 matching lines @@
   uint64_t size_;
   InitializationStateDcheck initialized_;
 
   DISALLOW_COPY_AND_ASSIGN(MemorySnapshotMac);
 };
 
 }  // namespace internal
 }  // namespace crashpad
 
 #endif  // CRASHPAD_SNAPSHOT_MAC_MEMORY_SNAPSHOT_MAC_H_