C++11 override style change for athena

chromeos/accelerometer/accelerometer_reader.h

 // Copyright 2014 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 CHROMEOS_ACCELEROMETER_ACCELEROMETER_READER_H_
 #define CHROMEOS_ACCELEROMETER_ACCELEROMETER_READER_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
@@ skipping 29 matching lines @@
 
     // Index of each accelerometer axis in data stream.
     int index[ui::ACCELEROMETER_SOURCE_COUNT][3];
   };
   typedef base::RefCountedData<ConfigurationData> Configuration;
   typedef base::RefCountedData<char[12]> Reading;
 
   // An interface to receive data from the AccelerometerReader.
   class Delegate {
    public:
+    virtual ~Delegate() {}
+
     virtual void HandleAccelerometerUpdate(
         const ui::AccelerometerUpdate& update) = 0;
   };
 
   AccelerometerReader(scoped_refptr<base::TaskRunner> blocking_task_runner,
                       Delegate* delegate);
   ~AccelerometerReader();
 
  private:
   // Dispatched when initialization is complete. If |success|, |configuration|
@@ skipping 22 matching lines @@
   scoped_refptr<Configuration> configuration_;
 
   base::WeakPtrFactory<AccelerometerReader> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AccelerometerReader);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_ACCELEROMETER_ACCELEROMETER_READER_H_