[reland] Move navigation-induced hiding of form-validation-bubble to the browser process.

third_party/WebKit/Source/core/page/ValidationMessageClient.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:
  * 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
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 38 matching lines @@
                                      TextDirection) = 0;
 
   // Hide validation message for the specified anchor if the message for the
   // anchor is already visible.
   virtual void HideValidationMessage(const Element& anchor) = 0;
 
   // Returns true if the validation message for the specified anchor element
   // is visible.
   virtual bool IsValidationMessageVisible(const Element& anchor) = 0;
 
-  virtual void WillUnloadDocument(const Document&) = 0;
   virtual void DocumentDetached(const Document&) = 0;
 
   virtual void WillBeDestroyed() = 0;
 
   DEFINE_INLINE_VIRTUAL_TRACE() {}
 };
 
 }  // namespace blink
 
 #endif