(Concept patch) Simplify WTF::HashTable::add() return value for size and performance

Source/core/dom/PresentationAttributeStyle.cpp

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 145 matching lines @@
 {
     DEFINE_STATIC_LOCAL(PresentationAttributeCacheCleaner, cacheCleaner, ());
 
     ASSERT(element.isStyledElement());
 
     PresentationAttributeCacheKey cacheKey;
     makePresentationAttributeCacheKey(element, cacheKey);
 
     unsigned cacheHash = computePresentationAttributeCacheHash(cacheKey);
 
-    PresentationAttributeCache::iterator cacheIterator;
+    PresentationAttributeCache::ValueType* cacheIterator;

[Erik Corry, 2014/02/04 14:27:15]

It seems wrong to call this 'iterator'.

     if (cacheHash) {
         cacheIterator = presentationAttributeCache().add(cacheHash, nullptr).iterator;
         if (cacheIterator->value && cacheIterator->value->key != cacheKey)
             cacheHash = 0;
     } else {
-        cacheIterator = presentationAttributeCache().end();
+        cacheIterator = 0;
     }
 
     RefPtr<StylePropertySet> style;
     if (cacheHash && cacheIterator->value) {
         style = cacheIterator->value->value;
         cacheCleaner.didHitPresentationAttributeCache();
     } else {
         style = MutableStylePropertySet::create(element.isSVGElement() ? SVGAttributeMode : HTMLAttributeMode);
         unsigned size = element.attributeCount();
         for (unsigned i = 0; i < size; ++i) {
@@ skipping 16 matching lines @@
         presentationAttributeCache().clear();
         presentationAttributeCache().set(cacheHash, newEntry.release());
     } else {
         cacheIterator->value = newEntry.release();
     }
 
     return style.release();
 }
 
 } // namespace WebCore