Revert 146726 "AXObjectCache gets recreated during document tear..."

Source/WebCore/dom/Document.cpp

Index: Source/WebCore/dom/Document.cpp
===================================================================
--- Source/WebCore/dom/Document.cpp	(revision 146890)
+++ Source/WebCore/dom/Document.cpp	(working copy)
@@ -629,8 +629,7 @@
 
     m_renderArena.clear();
 
-    if (this == topDocument())
-        clearAXObjectCache();
+    clearAXObjectCache();
 
     m_decoder = 0;
 
@@ -2212,40 +2211,23 @@
 
 void Document::clearAXObjectCache()
 {
-    ASSERT(topDocument() == this);
     // Clear the cache member variable before calling delete because attempts
     // are made to access it during destruction.
-    m_axObjectCache.clear();
+    topDocument()->m_axObjectCache.release();
 }
 
-AXObjectCache* Document::existingAXObjectCache() const
+bool Document::axObjectCacheExists() const
 {
-    if (!AXObjectCache::accessibilityEnabled())
-        return 0;
-
-    // If the renderer is gone then we are in the process of destruction.
-    // This method will be called before m_frame = 0.
-    if (!topDocument()->renderer())
-        return 0;
-
-    return topDocument()->m_axObjectCache.get();
+    return topDocument()->m_axObjectCache;
 }
 
 AXObjectCache* Document::axObjectCache() const
 {
-    if (!AXObjectCache::accessibilityEnabled())
-        return 0;
-    
     // The only document that actually has a AXObjectCache is the top-level
     // document.  This is because we need to be able to get from any WebCoreAXObject
     // to any other WebCoreAXObject on the same page.  Using a single cache allows
     // lookups across nested webareas (i.e. multiple documents).
     Document* topDocument = this->topDocument();
-
-    // If the document has already been detached, do not make a new axObjectCache.
-    if (!topDocument->renderer())
-        return 0;
-
     ASSERT(topDocument == this || !m_axObjectCache);
     if (!topDocument->m_axObjectCache)
         topDocument->m_axObjectCache = adoptPtr(new AXObjectCache(topDocument));
@@ -3494,12 +3476,10 @@
         }
     }
 
-    if (!focusChangeBlocked && m_focusedNode) {
-        // Create the AXObject cache in a focus change because Chromium relies on it.
-        if (AXObjectCache* cache = axObjectCache())
-            cache->handleFocusedUIElementChanged(oldFocusedNode.get(), newFocusedNode.get());
-    }
-
+#if PLATFORM(MAC) || PLATFORM(WIN) || PLATFORM(GTK) || PLATFORM(CHROMIUM)
+    if (!focusChangeBlocked && m_focusedNode && AXObjectCache::accessibilityEnabled())
+        axObjectCache()->handleFocusedUIElementChanged(oldFocusedNode.get(), newFocusedNode.get());
+#endif
     if (!focusChangeBlocked)
         page()->chrome()->focusedNodeChanged(m_focusedNode.get());