Add some missing virtual destructors to base classes.

base/trace_event/memory_dump_manager.h

 // Copyright 2015 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 BASE_TRACE_EVENT_MEMORY_DUMP_MANAGER_H_
 #define BASE_TRACE_EVENT_MEMORY_DUMP_MANAGER_H_
 
 #include <vector>
 
 #include "base/atomicops.h"
@@ skipping 108 matching lines @@
   friend struct DefaultSingletonTraits<MemoryDumpManager>;
   friend class MemoryDumpManagerDelegate;
   friend class MemoryDumpManagerTest;
   FRIEND_TEST_ALL_PREFIXES(MemoryDumpManagerTest, DisableFailingDumpers);
 
   static const int kMaxConsecutiveFailuresCount;
 
   static void SetInstanceForTesting(MemoryDumpManager* instance);
 
   MemoryDumpManager();
-  virtual ~MemoryDumpManager();
+  ~MemoryDumpManager() override;
 
   // Internal, used only by MemoryDumpManagerDelegate.
   // Creates a memory dump for the current process and appends it to the trace.
   // |callback| will be invoked asynchronously upon completion on the same
   // thread on which CreateProcessDump() was called.
   void CreateProcessDump(const MemoryDumpRequestArgs& args,
                          const MemoryDumpCallback& callback);
 
   bool InvokeDumpProviderLocked(MemoryDumpProvider* mdp,
                                 ProcessMemoryDump* pmd);
@@ skipping 61 matching lines @@
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MemoryDumpManagerDelegate);
 };
 
 }  // namespace trace_event
 }  // namespace base
 
 #endif  // BASE_TRACE_EVENT_MEMORY_DUMP_MANAGER_H_