Shrink QualifiedNameImpl by 8 bytes on 64-bit platforms

Review URL: https://codereview.chromium.org/560613002

git-svn-id: svn://svn.chromium.org/blink/trunk@181773 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/dom/QualifiedName.cpp

@@ -34,6 +34,13 @@
 
 namespace blink {
 
+struct SameSizeAsQualifiedNameImpl : public RefCounted<SameSizeAsQualifiedNameImpl> {
+    unsigned bitfield;
+    void* pointers[4];
+};
+
+COMPILE_ASSERT(sizeof(QualifiedName::QualifiedNameImpl) == sizeof(SameSizeAsQualifiedNameImpl), qualified_name_impl_should_stay_small);
+
 static const int staticQualifiedNamesCount = HTMLNames::HTMLTagsCount + HTMLNames::HTMLAttrsCount
     + MathMLNames::MathMLTagsCount + MathMLNames::MathMLAttrsCount
     + SVGNames::SVGTagsCount + SVGNames::SVGAttrsCount

third_party/WebKit/Source/core/dom/QualifiedName.h

@@ -74,22 +74,22 @@ public:
             RefCounted<QualifiedNameImpl>::deref();
         }
 
-        const AtomicString m_prefix;
-        const AtomicString m_localName;
-        const AtomicString m_namespace;
-        mutable AtomicString m_localNameUpper;
         // We rely on StringHasher's hashMemory clearing out the top 8 bits when
         // doing hashing and use one of the bits for the m_isStatic value.
         mutable unsigned m_existingHash : 24;
         unsigned m_isStatic : 1;
+        const AtomicString m_prefix;
+        const AtomicString m_localName;
+        const AtomicString m_namespace;
+        mutable AtomicString m_localNameUpper;
 
     private:
         QualifiedNameImpl(const AtomicString& prefix, const AtomicString& localName, const AtomicString& namespaceURI, bool isStatic)
-            : m_prefix(prefix)
+            : m_existingHash(0)
+            , m_isStatic(isStatic)
+            , m_prefix(prefix)
             , m_localName(localName)
             , m_namespace(namespaceURI)
-            , m_existingHash(0)
-            , m_isStatic(isStatic)
 
         {
             ASSERT(!namespaceURI.isEmpty() || namespaceURI.isNull());