Standardize usage of virtual/override/final in media/

media/cast/test/skewed_tick_clock.h

Index: media/cast/test/skewed_tick_clock.h
diff --git a/media/cast/test/skewed_tick_clock.h b/media/cast/test/skewed_tick_clock.h
index 3d5580fb3b681b18b39fab7457fa24b19ac1aa89..a5539a34c70d7d5b15f60daac669980466f7b2e3 100644
--- a/media/cast/test/skewed_tick_clock.h
+++ b/media/cast/test/skewed_tick_clock.h
@@ -25,7 +25,7 @@ class SkewedTickClock : public base::TickClock {
   // jump forwards or backwards, only changing the offset will
   // do that.
   void SetSkew(double skew, base::TimeDelta offset);
-  virtual base::TimeTicks NowTicks() override;
+  base::TimeTicks NowTicks() override;
 
  private:
   base::TimeTicks SkewTicks(base::TimeTicks now);