[Element / Autofill] Add boundsInViewportFloat() to fix <input> popup misalignment.

third_party/WebKit/Source/platform/scroll/Scrollbar.h

 /*
  * Copyright (C) 2004, 2006 Apple Computer, 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 112 matching lines @@
 
     // Used by some platform scrollbars to know when they've been released from capture.
     void mouseUp(const PlatformMouseEvent&);
     void mouseDown(const PlatformMouseEvent&);
 
     ScrollbarTheme* theme() const { return m_theme; }
 
     IntRect convertToContainingWidget(const IntRect&) const override;
     IntRect convertFromContainingWidget(const IntRect&) const override;
 
+    FloatRect convertToContainingWidget(const FloatRect&) const override;
+
     IntPoint convertToContainingWidget(const IntPoint&) const override;
     IntPoint convertFromContainingWidget(const IntPoint&) const override;
 
     void moveThumb(int pos, bool draggingDocument = false);
 
     bool isAlphaLocked() const override { return m_isAlphaLocked; }
     void setIsAlphaLocked(bool flag) override { m_isAlphaLocked = flag; }
 
     float elasticOverscroll() const override { return m_elasticOverscroll; }
     void setElasticOverscroll(float elasticOverscroll) override { m_elasticOverscroll = elasticOverscroll; }
@@ skipping 68 matching lines @@
 
     bool m_trackNeedsRepaint;
     bool m_thumbNeedsRepaint;
 };
 
 DEFINE_TYPE_CASTS(Scrollbar, Widget, widget, widget->isScrollbar(), widget.isScrollbar());
 
 } // namespace blink
 
 #endif // Scrollbar_h