Fix virtual/override/final usage in the rest of Source/core/.

Source/core/frame/DOMTimer.h

Index: Source/core/frame/DOMTimer.h
diff --git a/Source/core/frame/DOMTimer.h b/Source/core/frame/DOMTimer.h
index 508a1841884529871b964b78685b9a1f6be0da7d..866ac0bc5c93461d8df4eb1086f1da2f5cb3aaab 100644
--- a/Source/core/frame/DOMTimer.h
+++ b/Source/core/frame/DOMTimer.h
@@ -47,10 +47,10 @@ public:
     static int install(ExecutionContext*, PassOwnPtrWillBeRawPtr<ScheduledAction>, int timeout, bool singleShot);
     static void removeByID(ExecutionContext*, int timeoutID);
 
-    virtual ~DOMTimer();
+    ~DOMTimer() override;
 
     // ActiveDOMObject
-    virtual void stop() override;
+    void stop() override;
 
     // The following are essentially constants. All intervals are in seconds.
     static double hiddenPageAlignmentInterval();
@@ -74,10 +74,10 @@ private:
     }
 
     DOMTimer(ExecutionContext*, PassOwnPtrWillBeRawPtr<ScheduledAction>, int interval, bool singleShot, int timeoutID);
-    virtual void fired() override;
+    void fired() override;
 
     // Retuns timer fire time rounded to the next multiple of timer alignment interval.
-    virtual double alignedFireTime(double) const override;
+    double alignedFireTime(double) const override;
 
     int m_timeoutID;
     int m_nestingLevel;