Revert Implement <select> Popup Menu using PagePopup

Source/core/page/PagePopup.h

 /*
  * Copyright (C) 2012 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 13 matching lines @@
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef PagePopup_h
 #define PagePopup_h
 
-#include "wtf/Forward.h"
-
 namespace blink {
 
 class AXObject;
 
 // A PagePopup object is created by ChromeClient::openPagePopup(), and deleted
 // by ChromeClient::closePagePopup().
 class PagePopup {
 public:
     virtual AXObject* rootAXObject() = 0;
-    virtual void postMessage(const String& message) = 0;
 
 protected:
     virtual ~PagePopup() { }
 };
 
 }
 #endif