Shrinking CSSParserToken for lower CSS parsing memory usage.

Source/core/css/parser/CSSParserToken.h

Index: Source/core/css/parser/CSSParserToken.h
diff --git a/Source/core/css/parser/CSSParserToken.h b/Source/core/css/parser/CSSParserToken.h
index fe3d989b6fd9c665cd23fe0912db59f4a3953fa4..06edaaacaa54c0b1893d560983b22965c2e69a7d 100644
--- a/Source/core/css/parser/CSSParserToken.h
+++ b/Source/core/css/parser/CSSParserToken.h
@@ -87,8 +87,13 @@ public:
     void convertToPercentage();
 
     CSSParserTokenType type() const { return static_cast<CSSParserTokenType>(m_type); }
-    CSSParserString value() const { return m_value; }
-    bool valueEqualsIgnoringCase(const char* str) const { return m_value.equalIgnoringCase(str); }
+    CSSParserString value() const
+    {
+        CSSParserString ret;
+        ret.initRaw(m_valueDataCharRaw, m_valueLength, m_valueIs8Bit);
+        return ret;
+    }
+    bool valueEqualsIgnoringCase(const char* str) const { return value().equalIgnoringCase(str); }
 
     UChar delimiter() const;
     NumericSign numericSign() const;
@@ -105,13 +110,28 @@ public:
     void serialize(StringBuilder&) const;
 
 private:
+    void initValueFromCSSParserString(const CSSParserString& value)
+    {
+        m_valueLength = value.m_length;
+        m_valueIs8Bit = value.m_is8Bit;
+        m_valueDataCharRaw = value.m_data.charactersRaw;
+    }
     unsigned m_type : 6; // CSSParserTokenType
     unsigned m_blockType : 2; // BlockType
     unsigned m_numericValueType : 1; // NumericValueType
     unsigned m_numericSign : 2; // NumericSign
     unsigned m_unit : 7; // CSSPrimitiveValue::UnitType
 
-    CSSParserString m_value; // FIXME: Pack this better?
+    // m_value... is an unpacked CSSParserString so that we can pack it
+    // tightly with the rest of this object for a smaller object size.
+    bool m_valueIs8Bit : 1;
+    unsigned m_valueLength;
+
+    union {
+        const LChar* m_valueDataChar8;

[Timothy Loh, 2015/05/29 03:27:46]

We don't use the explicitly typed versions here.

+        const UChar* m_valueDataChar16;
+        const void* m_valueDataCharRaw;
+    };
 
     union {
         UChar m_delimiter;