Replaced HTMLIdentifier with an atomized string factory function

Source/core/html/parser/HTMLParserIdioms.cpp

 /*
  * Copyright (C) 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 11 matching lines @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "core/html/parser/HTMLParserIdioms.h"
 
 #include <limits>
 #include "wtf/MathExtras.h"
 #include "wtf/text/AtomicString.h"
 #include "wtf/text/StringBuilder.h"
+#include "wtf/text/StringHash.h"
 
 namespace WebCore {
 
 template <typename CharType>
 static String stripLeadingAndTrailingHTMLSpaces(String string, const CharType* characters, unsigned length)
 {
     unsigned numLeadingSpaces = 0;
     unsigned numTrailingSpaces = 0;
 
     for (; numLeadingSpaces < length; ++numLeadingSpaces) {
@@ skipping 229 matching lines @@
     if (a->hash() != b->hash())
         return false;
     return equalNonNull(a, b);
 }
 
 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;
 }
 
 }