Make blink classes and structures in core/css fast-allocated

Source/core/css/parser/CSSParserObserverWrapper.h

Index: Source/core/css/parser/CSSParserObserverWrapper.h
diff --git a/Source/core/css/parser/CSSParserObserverWrapper.h b/Source/core/css/parser/CSSParserObserverWrapper.h
index eb1ea2244e708eab318d91fca95d897c202483a3..510f4fdb9b2b39c78f48d5260e2adfe87f3d3e81 100644
--- a/Source/core/css/parser/CSSParserObserverWrapper.h
+++ b/Source/core/css/parser/CSSParserObserverWrapper.h
@@ -6,6 +6,7 @@
 #define CSSParserObserverWrapper_h
 
 #include "core/css/parser/CSSParserObserver.h"
+#include "wtf/Allocator.h"
 
 namespace blink {
 
@@ -42,6 +43,7 @@ private:
     CSSParserToken* m_firstParserToken;
 
     struct CommentPosition {
+        ALLOW_ONLY_INLINE_ALLOCATION();
         unsigned startOffset;
         unsigned endOffset;
         unsigned tokensBefore;