snapshot: Make destructors of interface classes public and virtual

snapshot/mac/thread_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 19 matching lines @@
 
 class ProcessReader;
 
 namespace internal {
 
 //! \brief A ThreadSnapshot of a thread in a running (or crashed) process on a
 //!     Mac OS X system.
 class ThreadSnapshotMac final : public ThreadSnapshot {
  public:
   ThreadSnapshotMac();
-  ~ThreadSnapshotMac();
+  ~ThreadSnapshotMac() override;
 
   //! \brief Initializes the object.
   //!
   //! \param[in] process_reader A ProcessReader for the task containing the
   //!     thread.
   //! \param[in] process_reader_thread The thread within the ProcessReader for
   //!     which the snapshot should be created.
   //!
   //! \return `true` if the snapshot could be created, `false` otherwise with
   //!     an appropriate message logged.
@@ skipping 25 matching lines @@
   int priority_;
   InitializationStateDcheck initialized_;
 
   DISALLOW_COPY_AND_ASSIGN(ThreadSnapshotMac);
 };
 
 }  // namespace internal
 }  // namespace crashpad
 
 #endif  // CRASHPAD_SNAPSHOT_MAC_THREAD_SNAPSHOT_MAC_H_