Chrome::client() should return a ChromeClient reference.

Source/core/accessibility/AXObjectCache.cpp

 /*
  * Copyright (C) 2008, 2009, 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 925 matching lines @@
             return;
         Document* document = toFrameView(scrollBar->parent())->frame()->document();
         if (document != document->topDocument())
             return;
         obj = get(document->renderer());
     }
 
     if (!obj || !obj->document() || !obj->documentFrameView() || !obj->documentFrameView()->frame() || !obj->documentFrameView()->frame()->page())
         return;
 
-    ChromeClient* client = obj->documentFrameView()->frame()->page()->chrome().client();
-    if (!client)
-        return;
+    ChromeClient& client = obj->documentFrameView()->frame()->page()->chrome().client();
 
     switch (notification) {
     case AXActiveDescendantChanged:
         if (!obj->document()->focusedElement() || (obj->node() != obj->document()->focusedElement()))
             break;
 
         // Calling handleFocusedUIElementChanged will focus the new active
         // descendant and send the AXFocusedUIElementChanged notification.
         handleFocusedUIElementChanged(0, obj->document()->focusedElement());
         break;
@@ skipping 12 matching lines @@
     case AXRowCountChanged:
     case AXRowExpanded:
     case AXScrolledToAnchor:
     case AXSelectedChildrenChanged:
     case AXSelectedTextChanged:
     case AXTextChanged:
     case AXValueChanged:
         break;
     }
 
-    client->postAccessibilityNotification(obj, notification);
+    client.postAccessibilityNotification(obj, notification);
 }
 
 void AXObjectCache::nodeTextChangePlatformNotification(AccessibilityObject*, AXTextChange, unsigned, const String&)
 {
 }
 
 void AXObjectCache::handleFocusedUIElementChanged(Node*, Node* newFocusedNode)
 {
     if (!newFocusedNode)
         return;
@@ skipping 12 matching lines @@
 void AXObjectCache::handleScrolledToAnchor(const Node* anchorNode)
 {
     // The anchor node may not be accessible. Post the notification for the
     // first accessible object.
     postPlatformNotification(AccessibilityObject::firstAccessibleObjectFromNode(anchorNode), AXScrolledToAnchor);
 }
 
 } // namespace WebCore
 
 #endif // HAVE(ACCESSIBILITY)