Fix virtual/override/final usage in Source/core/{fetch,loader,streams,xmlhttprequest}/.

Source/core/fetch/XSLStyleSheetResource.h

Index: Source/core/fetch/XSLStyleSheetResource.h
diff --git a/Source/core/fetch/XSLStyleSheetResource.h b/Source/core/fetch/XSLStyleSheetResource.h
index 9842e071d4942256807ec8f365e3c83802bac3a6..92cbf413559e8ac2bedb0be732dce34aba062951 100644
--- a/Source/core/fetch/XSLStyleSheetResource.h
+++ b/Source/core/fetch/XSLStyleSheetResource.h
@@ -40,7 +40,7 @@ public:
 
     const String& sheet() const { return m_sheet; }
 
-    virtual void didAddClient(ResourceClient*) override;
+    void didAddClient(ResourceClient*) override;
 
 protected:
     class XSLStyleSheetResourceFactory : public ResourceFactory {
@@ -55,7 +55,7 @@ protected:
     };
     XSLStyleSheetResource(const ResourceRequest&, const String& charset);
 
-    virtual void checkNotify() override;
+    void checkNotify() override;
 
     String m_sheet;
 };