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

base/debug/trace_event_system_stats_monitor.cc

 // 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.
 
 #include "base/debug/trace_event_system_stats_monitor.h"
 
 #include "base/debug/leak_annotations.h"
 #include "base/debug/trace_event.h"
 #include "base/json/json_writer.h"
 #include "base/lazy_instance.h"
@@ skipping 13 matching lines @@
 // Holds profiled system stats until the tracing system needs to serialize it.
 class SystemStatsHolder : public base::debug::ConvertableToTraceFormat {
  public:
   SystemStatsHolder() { }
 
   // Fills system_metrics_ with profiled system memory and disk stats.
   // Uses the previous stats to compute rates if this is not the first profile.
   void GetSystemProfilingStats();
 
   // base::debug::ConvertableToTraceFormat overrides:
-  virtual void AppendAsTraceFormat(std::string* out) const OVERRIDE {
+  void AppendAsTraceFormat(std::string* out) const override {
     AppendSystemProfileAsTraceFormat(system_stats_, out);
   }
 
  private:
   virtual ~SystemStatsHolder() { }
 
   SystemMetrics system_stats_;
 
   DISALLOW_COPY_AND_ASSIGN(SystemStatsHolder);
 };
@@ skipping 79 matching lines @@
 
 void AppendSystemProfileAsTraceFormat(const SystemMetrics& system_metrics,
                                       std::string* output) {
   std::string tmp;
   base::JSONWriter::Write(system_metrics.ToValue().get(), &tmp);
   *output += tmp;
 }
 
 }  // namespace debug
 }  // namespace base