[Experimental] CSSSerializer Proof-of-concept

third_party/WebKit/Source/core/css/CSSValue.h

Index: third_party/WebKit/Source/core/css/CSSValue.h
diff --git a/third_party/WebKit/Source/core/css/CSSValue.h b/third_party/WebKit/Source/core/css/CSSValue.h
index 69c3d0ac57366d6745d7c5416d0847d148fc85b9..310f0e8a52f175933d8ccbe3fc8d0579dde6d586 100644
--- a/third_party/WebKit/Source/core/css/CSSValue.h
+++ b/third_party/WebKit/Source/core/css/CSSValue.h
@@ -31,6 +31,9 @@
 
 namespace blink {
 
+class CSSDeserializeStream;
+class CSSSerializeStream;
+
 class CORE_EXPORT CSSValue : public RefCountedWillBeGarbageCollectedFinalized<CSSValue> {
 #if ENABLE(OILPAN)
 public:
@@ -112,6 +115,9 @@ public:
 
     bool equals(const CSSValue&) const;
 
+    static PassRefPtrWillBeRawPtr<CSSValue> deserialize(CSSDeserializeStream*);
+    void serialize(CSSSerializeStream*) const;
+
     void finalizeGarbageCollectedObject();
     DEFINE_INLINE_TRACE_AFTER_DISPATCH() { }
     DECLARE_TRACE();
@@ -122,7 +128,8 @@ public:
     // 'source\wtf\refcounted.h' by using msvc.
     ~CSSValue() { }
 
-protected:
+    //  protected:
+public:
     static const size_t ClassTypeBits = 6;
     enum ClassType {
         PrimitiveClass,
@@ -212,13 +219,31 @@ protected:
     // to maximize struct packing.
 
     // CSSPrimitiveValue bits:
-    unsigned m_primitiveUnitType : 7; // CSSPrimitiveValue::UnitType
-    mutable unsigned m_hasCachedCSSText : 1;
+    union {
+        struct {
+            unsigned m_primitiveUnitType : 7; // CSSPrimitiveValue::UnitType
+            mutable unsigned m_hasCachedCSSText : 1;
 
-    unsigned m_valueListSeparator : ValueListSeparatorBits;
+            unsigned m_valueListSeparator : ValueListSeparatorBits;
 
-private:
-    unsigned m_classType : ClassTypeBits; // ClassType
+            // private:
+            unsigned m_classType : ClassTypeBits; // ClassType
+        };
+        unsigned m_bitfields;
+    };
+
+    union aaaa {
+        struct {
+            unsigned m_primitiveUnitType : 7; // CSSPrimitiveValue::UnitType
+            mutable unsigned m_hasCachedCSSText : 1;
+
+            unsigned m_valueListSeparator : ValueListSeparatorBits;
+
+            // private:
+            unsigned m_classType : ClassTypeBits; // ClassType
+        };
+        unsigned m_bitfields;
+    };
 };
 
 template<typename CSSValueType, size_t inlineCapacity>
@@ -268,6 +293,23 @@ inline bool compareCSSValuePtr(const Member<CSSValueType>& first, const Member<C
     return first->equals(*second);
 }
 
+template<typename T> class CSSSerializeTrait;
+template<> class CSSSerializeTrait<CSSValue> {
+public:
+    static void serializeNull(CSSSerializeStream*);
+    static void serializeNonNullHeader(CSSSerializeStream*) { }
+};
+
+template<typename T> class CSSDeserializeTrait;
+template<> class CSSDeserializeTrait<CSSValue> {
+public:
+    static bool deserializeNonNullHeader(CSSDeserializeStream*)
+    { 
+        // CSSValue::deserialize will return nullptr if needed.
+        return true;
+    }
+};
+
 #define DEFINE_CSS_VALUE_TYPE_CASTS(thisType, predicate) \
     DEFINE_TYPE_CASTS(thisType, CSSValue, value, value->predicate, value.predicate)