Cache cssomWrappers for StylePropertySets directly on the MutableStylePropertySet.

Source/core/css/StylePropertySet.cpp

Index: Source/core/css/StylePropertySet.cpp
diff --git a/Source/core/css/StylePropertySet.cpp b/Source/core/css/StylePropertySet.cpp
index 81467555886c2c1843a5b55395a29910d6d99ea4..e5f28cfe5284ae6f6cb856fb81f8fa28913ed45e 100644
--- a/Source/core/css/StylePropertySet.cpp
+++ b/Source/core/css/StylePropertySet.cpp
@@ -42,13 +42,6 @@ using namespace std;
 
 namespace WebCore {
 
-typedef HashMap<MutableStylePropertySet*, OwnPtr<PropertySetCSSStyleDeclaration> > PropertySetCSSOMWrapperMap;
-static PropertySetCSSOMWrapperMap& propertySetCSSOMWrapperMap()
-{
-    DEFINE_STATIC_LOCAL(PropertySetCSSOMWrapperMap, propertySetCSSOMWrapperMapInstance, ());
-    return propertySetCSSOMWrapperMapInstance;
-}
-
 static size_t sizeForImmutableStylePropertySetWithPropertyCount(unsigned count)
 {
     return sizeof(ImmutableStylePropertySet) - sizeof(void*) + sizeof(CSSValue*) * count + sizeof(StylePropertyMetadata) * count;
@@ -68,6 +61,11 @@ PassRefPtr<ImmutableStylePropertySet> StylePropertySet::immutableCopyIfNeeded()
     return ImmutableStylePropertySet::create(mutableThis->m_propertyVector.data(), mutableThis->m_propertyVector.size(), cssParserMode());
 }
 
+MutableStylePropertySet::MutableStylePropertySet(CSSParserMode cssParserMode)
+    : StylePropertySet(cssParserMode)
+{
+}
+
 MutableStylePropertySet::MutableStylePropertySet(const CSSProperty* properties, unsigned length)
     : StylePropertySet(CSSStrictMode)
 {
@@ -107,13 +105,6 @@ MutableStylePropertySet::MutableStylePropertySet(const StylePropertySet& other)
     }
 }
 
-MutableStylePropertySet::~MutableStylePropertySet()
-{
-    ASSERT(!m_ownsCSSOMWrapper || propertySetCSSOMWrapperMap().contains(this));
-    if (m_ownsCSSOMWrapper)
-        propertySetCSSOMWrapperMap().remove(this);
-}
-
 String StylePropertySet::getPropertyValue(CSSPropertyID propertyID) const
 {
     RefPtr<CSSValue> value = getPropertyCSSValue(propertyID);
@@ -328,6 +319,11 @@ String StylePropertySet::asText() const
     return StylePropertySerializer(*this).asText();
 }
 
+bool StylePropertySet::hasCSSOMWrapper() const
+{
+    return m_isMutable && static_cast<const MutableStylePropertySet*>(this)->m_cssomWrapper;
+}
+
 void MutableStylePropertySet::mergeAndOverrideOnConflict(const StylePropertySet* other)
 {
     ASSERT(isMutable());
@@ -515,34 +511,28 @@ PassRefPtr<MutableStylePropertySet> StylePropertySet::copyPropertiesInSet(const
 
 PropertySetCSSStyleDeclaration* MutableStylePropertySet::cssStyleDeclaration()
 {
-    if (!m_ownsCSSOMWrapper)
-        return 0;
-    return propertySetCSSOMWrapperMap().get(this);
+    return m_cssomWrapper.get();
 }
 
 CSSStyleDeclaration* MutableStylePropertySet::ensureCSSStyleDeclaration()
 {
-    if (m_ownsCSSOMWrapper) {
-        ASSERT(!static_cast<CSSStyleDeclaration*>(propertySetCSSOMWrapperMap().get(this))->parentRule());
-        ASSERT(!propertySetCSSOMWrapperMap().get(this)->parentElement());
-        return propertySetCSSOMWrapperMap().get(this);
+    if (m_cssomWrapper) {
+        ASSERT(!static_cast<CSSStyleDeclaration*>(m_cssomWrapper.get())->parentRule());
+        ASSERT(!m_cssomWrapper->parentElement());
+        return m_cssomWrapper.get();
     }
-    m_ownsCSSOMWrapper = true;
-    PropertySetCSSStyleDeclaration* cssomWrapper = new PropertySetCSSStyleDeclaration(this);
-    propertySetCSSOMWrapperMap().add(this, adoptPtr(cssomWrapper));
-    return cssomWrapper;
+    m_cssomWrapper = adoptPtr(new PropertySetCSSStyleDeclaration(this));
+    return m_cssomWrapper.get();
 }
 
 CSSStyleDeclaration* MutableStylePropertySet::ensureInlineCSSStyleDeclaration(Element* parentElement)
 {
-    if (m_ownsCSSOMWrapper) {
-        ASSERT(propertySetCSSOMWrapperMap().get(this)->parentElement() == parentElement);
-        return propertySetCSSOMWrapperMap().get(this);
+    if (m_cssomWrapper) {
+        ASSERT(m_cssomWrapper->parentElement() == parentElement);
+        return m_cssomWrapper.get();
     }
-    m_ownsCSSOMWrapper = true;
-    PropertySetCSSStyleDeclaration* cssomWrapper = new InlineCSSStyleDeclaration(this, parentElement);
-    propertySetCSSOMWrapperMap().add(this, adoptPtr(cssomWrapper));
-    return cssomWrapper;
+    m_cssomWrapper = adoptPtr(new InlineCSSStyleDeclaration(this, parentElement));
+    return m_cssomWrapper.get();
 }
 
 unsigned StylePropertySet::averageSizeInBytes()