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

Source/WebCore/html/HTMLSelectElement.cpp

Index: Source/WebCore/html/HTMLSelectElement.cpp
===================================================================
--- Source/WebCore/html/HTMLSelectElement.cpp	(revision 146890)
+++ Source/WebCore/html/HTMLSelectElement.cpp	(working copy)
@@ -380,10 +380,8 @@
     setRecalcListItems();
     setNeedsValidityCheck();
 
-    if (renderer()) {
-        if (AXObjectCache* cache = renderer()->document()->existingAXObjectCache())
-            cache->childrenChanged(this);
-    }
+    if (AXObjectCache::accessibilityEnabled() && renderer())
+        renderer()->document()->axObjectCache()->childrenChanged(this);
 }
 
 void HTMLSelectElement::accessKeyAction(bool sendMouseEvents)
@@ -724,10 +722,8 @@
     if (!inDocument())
         invalidateSelectedItems();
     
-    if (renderer()) {
-        if (AXObjectCache* cache = renderer()->document()->existingAXObjectCache())
-            cache->childrenChanged(this);
-    }
+    if (AXObjectCache::accessibilityEnabled() && renderer())
+        renderer()->document()->axObjectCache()->childrenChanged(this);
 }
 
 void HTMLSelectElement::recalcListItems(bool updateSelectedStates) const