message: Fix erroneous comment in StopWatch
diff: @@ -42,7 +42,7 @@ public:
  /// Clear the elapsed time on the stopwatch and restart it if it's running.
  void Clear();
  - /// Clear the elapsed time and start the stopwatch.
  + /// Start the stopwatch. The elapsed time is @b not cleared.
  void Start();
  /// Stop the stopwatch.
  