Fix virtual/override/final usage in Source/web/.

Source/web/ContextFeaturesClientImpl.h

Index: Source/web/ContextFeaturesClientImpl.h
diff --git a/Source/web/ContextFeaturesClientImpl.h b/Source/web/ContextFeaturesClientImpl.h
index 8ac7dbedc5adf0f757ab9d1d6c99d2aad7bcf999..64b5b07aee991c4e3f62854cb1971baf0470ae5b 100644
--- a/Source/web/ContextFeaturesClientImpl.h
+++ b/Source/web/ContextFeaturesClientImpl.h
@@ -42,8 +42,8 @@ public:
         return adoptPtr(new ContextFeaturesClientImpl());
     }
 
-    virtual bool isEnabled(Document*, ContextFeatures::FeatureType, bool defaultValue) override;
-    virtual void urlDidChange(Document*) override;
+    bool isEnabled(Document*, ContextFeatures::FeatureType, bool defaultValue) override;
+    void urlDidChange(Document*) override;
 
 private:
     ContextFeaturesClientImpl() { }