Add missing virtual keyword for methods with OVERRIDE

Source/core/animation/TimedItemTest.cpp

Index: Source/core/animation/TimedItemTest.cpp
diff --git a/Source/core/animation/TimedItemTest.cpp b/Source/core/animation/TimedItemTest.cpp
index 6bd34ab67cc3785ac192fbb0bdcd23b519ce4979..8742f481448c6d3ba6bc61fc543c1776d5512475 100644
--- a/Source/core/animation/TimedItemTest.cpp
+++ b/Source/core/animation/TimedItemTest.cpp
@@ -39,7 +39,7 @@ namespace {
 
 class TestTimedItemEventDelegate : public TimedItem::EventDelegate {
 public:
-    void onEventCondition(const TimedItem* timedItem, bool isFirstSample, TimedItem::Phase previousPhase, double previousIteration) OVERRIDE
+    virtual void onEventCondition(const TimedItem* timedItem, bool isFirstSample, TimedItem::Phase previousPhase, double previousIteration) OVERRIDE
     {
         m_eventTriggered = true;
         m_phaseChanged = previousPhase != timedItem->phase();
@@ -75,10 +75,10 @@ public:
         TimedItem::updateInheritedTime(time);
     }
 
-    bool updateChildrenAndEffects() const OVERRIDE { return false; }
+    virtual bool updateChildrenAndEffects() const OVERRIDE { return false; }
     void willDetach() { }
     TestTimedItemEventDelegate* eventDelegate() { return m_eventDelegate; }
-    double calculateTimeToEffectChange(double localTime, double timeToNextIteration) const OVERRIDE
+    virtual double calculateTimeToEffectChange(double localTime, double timeToNextIteration) const OVERRIDE
     {
         m_localTime = localTime;
         m_timeToNextIteration = timeToNextIteration;