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

Source/WebCore/editing/InsertIntoTextNodeCommand.cpp

Index: Source/WebCore/editing/InsertIntoTextNodeCommand.cpp
===================================================================
--- Source/WebCore/editing/InsertIntoTextNodeCommand.cpp	(revision 146890)
+++ Source/WebCore/editing/InsertIntoTextNodeCommand.cpp	(working copy)
@@ -63,8 +63,8 @@
 
     m_node->insertData(m_offset, m_text, IGNORE_EXCEPTION);
 
-    if (AXObjectCache* cache = document()->existingAXObjectCache())
-        cache->nodeTextChangeNotification(m_node.get(), AXObjectCache::AXTextInserted, m_offset, m_text);
+    if (AXObjectCache::accessibilityEnabled())
+        document()->axObjectCache()->nodeTextChangeNotification(m_node.get(), AXObjectCache::AXTextInserted, m_offset, m_text);
 }
 
 void InsertIntoTextNodeCommand::doUnapply()
@@ -73,8 +73,8 @@
         return;
         
     // Need to notify this before actually deleting the text
-    if (AXObjectCache* cache = document()->existingAXObjectCache())
-        cache->nodeTextChangeNotification(m_node.get(), AXObjectCache::AXTextDeleted, m_offset, m_text);
+    if (AXObjectCache::accessibilityEnabled())
+        document()->axObjectCache()->nodeTextChangeNotification(m_node.get(), AXObjectCache::AXTextDeleted, m_offset, m_text);
 
     m_node->deleteData(m_offset, m_text.length(), IGNORE_EXCEPTION);
 }