Revert of Expose multiline attribute from blink

public/web/WebAXEnums.h

 /*
  * Copyright (C) 2013 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 187 matching lines @@
     WebAXStateChecked,
     WebAXStateEnabled,
     WebAXStateExpanded,
     WebAXStateFocusable,
     WebAXStateFocused,
     WebAXStateHaspopup,
     WebAXStateHovered,
     WebAXStateIndeterminate,
     WebAXStateInvisible,
     WebAXStateLinked,
-    WebAXStateMultiline,
     WebAXStateMultiselectable,
     WebAXStateOffscreen,
     WebAXStatePressed,
     WebAXStateProtected,
     WebAXStateReadonly,
     WebAXStateRequired,
     WebAXStateSelectable,
     WebAXStateSelected,
     WebAXStateVertical,
     WebAXStateVisited,
@@ skipping 50 matching lines @@
     WebAXInvalidStateFalse,
     WebAXInvalidStateTrue,
     WebAXInvalidStateSpelling,
     WebAXInvalidStateGrammar,
     WebAXInvalidStateOther
 };
 
 } // namespace blink
 
 #endif