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

Source/WebCore/editing/InsertNodeBeforeCommand.cpp

Index: Source/WebCore/editing/InsertNodeBeforeCommand.cpp
===================================================================
--- Source/WebCore/editing/InsertNodeBeforeCommand.cpp	(revision 146890)
+++ Source/WebCore/editing/InsertNodeBeforeCommand.cpp	(working copy)
@@ -57,8 +57,8 @@
 
     parent->insertBefore(m_insertChild.get(), m_refChild.get(), IGNORE_EXCEPTION, AttachLazily);
 
-    if (AXObjectCache* cache = document()->existingAXObjectCache())
-        cache->nodeTextChangeNotification(m_insertChild.get(), AXObjectCache::AXTextInserted, 0, m_insertChild->nodeValue());
+    if (AXObjectCache::accessibilityEnabled())
+        document()->axObjectCache()->nodeTextChangeNotification(m_insertChild.get(), AXObjectCache::AXTextInserted, 0, m_insertChild->nodeValue());
 }
 
 void InsertNodeBeforeCommand::doUnapply()
@@ -67,8 +67,8 @@
         return;
 
     // Need to notify this before actually deleting the text
-    if (AXObjectCache* cache = document()->existingAXObjectCache())
-        cache->nodeTextChangeNotification(m_insertChild.get(), AXObjectCache::AXTextDeleted, 0, m_insertChild->nodeValue());
+    if (AXObjectCache::accessibilityEnabled())
+        document()->axObjectCache()->nodeTextChangeNotification(m_insertChild.get(), AXObjectCache::AXTextDeleted, 0, m_insertChild->nodeValue());
 
     m_insertChild->remove(IGNORE_EXCEPTION);
 }