Make classes and structures in core/html fast-allocated.

Source/core/html/track/vtt/VTTToken.h

Index: Source/core/html/track/vtt/VTTToken.h
diff --git a/Source/core/html/track/vtt/VTTToken.h b/Source/core/html/track/vtt/VTTToken.h
index 4bcbadf8a97804ec5d38aacb645b66489c1a583c..f1b8f2dd0ae0deb06ec14125e10fde4a49a4690a 100644
--- a/Source/core/html/track/vtt/VTTToken.h
+++ b/Source/core/html/track/vtt/VTTToken.h
@@ -31,9 +31,12 @@
 #ifndef VTTToken_h
 #define VTTToken_h
 
+#include "wtf/Allocator.h"
+
 namespace blink {
 
 class VTTTokenTypes {
+    STATIC_ONLY(VTTTokenTypes);
 public:
     enum Type {
         Uninitialized,
@@ -45,6 +48,7 @@ public:
 };
 
 class VTTToken {
+    STACK_ALLOCATED();
 public:
     typedef VTTTokenTypes Type;