Replaced HTMLIdentifier with an atomized string factory function

Source/core/html/parser/HTMLParserIdioms.cpp

Index: Source/core/html/parser/HTMLParserIdioms.cpp
diff --git a/Source/core/html/parser/HTMLParserIdioms.cpp b/Source/core/html/parser/HTMLParserIdioms.cpp
index 2173ef531261f3be7ebcc273d7cee35f4005d787..f538c54cc5bfc600db038025427f6b21559c110a 100644
--- a/Source/core/html/parser/HTMLParserIdioms.cpp
+++ b/Source/core/html/parser/HTMLParserIdioms.cpp
@@ -29,6 +29,7 @@
 #include "wtf/MathExtras.h"
 #include "wtf/text/AtomicString.h"
 #include "wtf/text/StringBuilder.h"
+#include "wtf/text/StringHash.h"
 
 namespace WebCore {
 
@@ -278,9 +279,31 @@ bool threadSafeMatch(const QualifiedName& a, const QualifiedName& b)
     return threadSafeEqual(a.localName().impl(), b.localName().impl());
 }
 
-bool threadSafeMatch(const HTMLIdentifier& localName, const QualifiedName& qName)
+bool threadSafeMatch(const String& localName, const QualifiedName& qName)
 {
-    return threadSafeEqual(localName.asStringImpl(), qName.localName().impl());
+    return threadSafeEqual(localName.impl(), qName.localName().impl());
+}
+
+StringImpl* findStringIfStatic(const UChar* characters, unsigned length)
+{
+    // We don't need to try hashing if we know the string is too long.
+    if (length > StringImpl::highestStaticStringLength())
+        return 0;
+    // computeHashAndMaskTop8Bits is the function StringImpl::hash() uses.
+    unsigned hash = StringHasher::computeHashAndMaskTop8Bits(characters, length);
+    const WTF::StaticStringsTable& table = StringImpl::allStaticStrings();
+    ASSERT(!table.isEmpty());
+
+    WTF::StaticStringsTable::const_iterator it = table.find(hash);
+    if (it == table.end())
+        return 0;
+    // It's possible to have hash collisions between arbitrary strings and
+    // known identifiers (e.g. "bvvfg" collides with "script").
+    // However ASSERTs in StringImpl::createStatic guard against there ever being collisions
+    // between static strings.
+    if (!equal(it->value, characters, length))
+        return 0;
+    return it->value;
 }
 
 }