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

third_party/WebKit/Source/core/page/ValidationMessageClientImpl.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 45 matching lines @@
   void CheckAnchorStatus(TimerBase*);
   LocalFrameView* CurrentView();
 
   void ShowValidationMessage(const Element& anchor,
                              const String& message,
                              TextDirection message_dir,
                              const String& sub_message,
                              TextDirection sub_message_dir) override;
   void HideValidationMessage(const Element& anchor) override;
   bool IsValidationMessageVisible(const Element& anchor) override;
-  void WillUnloadDocument(const Document&) override;
   void DocumentDetached(const Document&) override;
   void WillBeDestroyed() override;
 
   // PopupOpeningObserver function
   void WillOpenPopup() override;
 
   WebViewBase& web_view_;
   Member<const Element> current_anchor_;
   String message_;
   IntRect last_anchor_rect_in_screen_;
   float last_page_scale_factor_;
   double finish_time_;
   std::unique_ptr<TimerBase> timer_;
 };
 
 }  // namespace blink
 
 #endif