Use FINAL macro for classes whose virtual destructor was removed

Source/core/css/Pair.h

Index: Source/core/css/Pair.h
diff --git a/Source/core/css/Pair.h b/Source/core/css/Pair.h
index dd70239f71eae2dfd10029c4db58cbeaca0f04c0..fc2edaa828b4be885a0111deabbe05a9fe4be490 100644
--- a/Source/core/css/Pair.h
+++ b/Source/core/css/Pair.h
@@ -32,7 +32,7 @@ namespace WebCore {
 // and border-spacing (all of which are space-separated sets of two values).  At the moment we are only using it for
 // border-radius and background-size, but (FIXME) border-spacing and background-position could be converted over to use
 // it (eliminating some extra -webkit- internal properties).
-class Pair : public RefCounted<Pair> {
+class Pair FINAL : public RefCounted<Pair> {
 public:
     enum IdenticalValuesPolicy { DropIdenticalValues, KeepIdenticalValues };