Refactor ScopedAXObjectCache to remove ref count

Source/core/dom/AXObjectCache.cpp

Index: Source/core/dom/AXObjectCache.cpp
diff --git a/Source/core/dom/AXObjectCache.cpp b/Source/core/dom/AXObjectCache.cpp
index 340616585a1efceb73bd691051ee2524ed4b56dc..a9a27663041122eef409ca11937e1d64756a02ef 100644
--- a/Source/core/dom/AXObjectCache.cpp
+++ b/Source/core/dom/AXObjectCache.cpp
@@ -40,7 +40,7 @@ void AXObjectCache::init(AXObjectCacheCreateFunction function)
     m_createFunction = function;
 }
 
-AXObjectCache* AXObjectCache::create(Document& document)
+PassOwnPtr<AXObjectCache> AXObjectCache::create(Document& document)
 {
     ASSERT(m_createFunction);
     return (m_createFunction)(document);
@@ -55,24 +55,17 @@ AXObjectCache::~AXObjectCache()
 }
 
 ScopedAXObjectCache::ScopedAXObjectCache(Document& document)
-    : m_document(document)
-    , m_cache(0)
+    : m_ownedCache(nullptr)
+    , m_cache(nullptr)
 {
     if (AXObjectCache* existingCache = document.axObjectCache()) {
         m_cache = existingCache;
-        m_isScoped = false;
     } else {
-        m_isScoped = true;
-        m_cache = AXObjectCache::create(m_document);
+        m_ownedCache = AXObjectCache::create(document);
+        m_cache = m_ownedCache.get();
     }
 }
 
-ScopedAXObjectCache::~ScopedAXObjectCache()
-{
-    if (m_isScoped)
-        delete m_cache;
-}
-
 AXObjectCache* ScopedAXObjectCache::get()
 {
     ASSERT(m_cache);