Fix virtual/override/final usage in Source/core/xml/.

Source/core/xml/XSLStyleSheet.h

Index: Source/core/xml/XSLStyleSheet.h
diff --git a/Source/core/xml/XSLStyleSheet.h b/Source/core/xml/XSLStyleSheet.h
index f757e878ba31257546ed49a5188e76a2ebcee5c8..ba3a09ea232b8bcba3008bdbf193bff55d237bbe 100644
--- a/Source/core/xml/XSLStyleSheet.h
+++ b/Source/core/xml/XSLStyleSheet.h
@@ -61,7 +61,7 @@ public:
         return adoptRefWillBeNoop(new XSLStyleSheet(document, stylesheetRootNode, originalURL, finalURL, false));
     }
 
-    virtual ~XSLStyleSheet();
+    ~XSLStyleSheet() override;
 
     bool parseString(const String&);
 
@@ -73,7 +73,7 @@ public:
     void loadChildSheet(const String& href);
 
     Document* ownerDocument();
-    virtual XSLStyleSheet* parentStyleSheet() const override { return m_parentStyleSheet; }
+    XSLStyleSheet* parentStyleSheet() const override { return m_parentStyleSheet; }
     void setParentStyleSheet(XSLStyleSheet*);
 
     xmlDocPtr document();
@@ -85,16 +85,16 @@ public:
     void markAsProcessed();
     bool processed() const { return m_processed; }
 
-    virtual String type() const override { return "text/xml"; }
-    virtual bool disabled() const override { return m_isDisabled; }
-    virtual void setDisabled(bool b) override { m_isDisabled = b; }
-    virtual Node* ownerNode() const override { return m_ownerNode; }
-    virtual String href() const override { return m_originalURL; }
-    virtual String title() const override { return emptyString(); }
+    String type() const override { return "text/xml"; }
+    bool disabled() const override { return m_isDisabled; }
+    void setDisabled(bool b) override { m_isDisabled = b; }
+    Node* ownerNode() const override { return m_ownerNode; }
+    String href() const override { return m_originalURL; }
+    String title() const override { return emptyString(); }
 
-    virtual void clearOwnerNode() override { m_ownerNode = nullptr; }
-    virtual KURL baseURL() const override { return m_finalURL; }
-    virtual bool isLoading() const override;
+    void clearOwnerNode() override { m_ownerNode = nullptr; }
+    KURL baseURL() const override { return m_finalURL; }
+    bool isLoading() const override;
 
     DECLARE_VIRTUAL_TRACE();