replace 'virtual ... OVERRIDE' with '... override'

base/metrics/histogram_delta_serialization.h

 // Copyright 2013 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_METRICS_HISTOGRAM_DELTA_SERIALIZATION_H_
 #define BASE_METRICS_HISTOGRAM_DELTA_SERIALIZATION_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 20 matching lines @@
   // will compute the deltas relative to this one.
   void PrepareAndSerializeDeltas(std::vector<std::string>* serialized_deltas);
 
   // Deserialize deltas and add samples to corresponding histograms, creating
   // them if necessary. Silently ignores errors in |serialized_deltas|.
   static void DeserializeAndAddSamples(
       const std::vector<std::string>& serialized_deltas);
 
  private:
   // HistogramFlattener implementation.
-  virtual void RecordDelta(const HistogramBase& histogram,
-                           const HistogramSamples& snapshot) OVERRIDE;
+  void RecordDelta(const HistogramBase& histogram,
+                   const HistogramSamples& snapshot) override;
   virtual void InconsistencyDetected(
-      HistogramBase::Inconsistency problem) OVERRIDE;
-  virtual void UniqueInconsistencyDetected(
-      HistogramBase::Inconsistency problem) OVERRIDE;
-  virtual void InconsistencyDetectedInLoggedCount(int amount) OVERRIDE;
+      HistogramBase::Inconsistency problem) override;
+  void UniqueInconsistencyDetected(
+      HistogramBase::Inconsistency problem) override;
+  void InconsistencyDetectedInLoggedCount(int amount) override;
 
   // Calculates deltas in histogram counters.
   HistogramSnapshotManager histogram_snapshot_manager_;
 
   // Output buffer for serialized deltas.
   std::vector<std::string>* serialized_deltas_;
 
   // Histograms to count inconsistencies in snapshots.
   HistogramBase* inconsistencies_histogram_;
   HistogramBase* inconsistencies_unique_histogram_;
   HistogramBase* inconsistent_snapshot_histogram_;
 
   DISALLOW_COPY_AND_ASSIGN(HistogramDeltaSerialization);
 };
 
 }  // namespace base
 
 #endif  // BASE_METRICS_HISTOGRAM_DELTA_SERIALIZATION_H_