Implement computedRole and computedName (behind a flag)

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 d9e64928a742bd192e0877b4ca151e9e930461d7..0411f271c29eea21aac8d5fae938b277b34a0930 100644
--- a/Source/core/dom/AXObjectCache.cpp
+++ b/Source/core/dom/AXObjectCache.cpp
@@ -40,4 +40,34 @@ AXObjectCache::~AXObjectCache()
 {
 }
 
+ScopedAXObjectCache::ScopedAXObjectCache(Document& document)
+    : m_document(document)
+    , m_cache(0)
+{
+    if (AXObjectCache* existingCache = document.axObjectCache()) {
+        m_cache = existingCache;
+        m_isScoped = false;
+    } else {
+        m_isScoped = true;
+        m_cache = AXObjectCache::create(m_document);
+    }
+}
+
+ScopedAXObjectCache::~ScopedAXObjectCache()
+{
+    if (m_isScoped)
+        delete m_cache;
+}
+
+AXObjectCache* ScopedAXObjectCache::get()
+{
+    ASSERT(m_cache);
+    return m_cache;
+}
+
+AXObjectCache* ScopedAXObjectCache::operator->()
+{
+    return get();
+}
+
 } // namespace blink