Revert of Expose multiline attribute from blink

Source/web/WebAXObject.cpp

 /*
  * Copyright (C) 2009 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 510 matching lines @@
     m_private->ariaLabelledbyElements(labelledby);
 
     WebVector<WebAXObject> result(labelledby.size());
     for (size_t i = 0; i < labelledby.size(); i++)
         result[i] = WebAXObject(labelledby[i]);
     labelledbyElements.swap(result);
 
     return true;
 }
 
-bool WebAXObject::isMultiline() const
-{
-    if (isDetached())
-        return false;
-
-    return m_private->isMultiline();
-}
-
 bool WebAXObject::isInLiveRegion() const
 {
     if (isDetached())
         return false;
 
     return 0 != m_private->liveRegionRoot();
 }
 
 bool WebAXObject::liveRegionAtomic() const
 {
@@ skipping 792 matching lines @@
     m_private = object;
     return *this;
 }
 
 WebAXObject::operator WTF::PassRefPtr<AXObject>() const
 {
     return m_private.get();
 }
 
 } // namespace blink