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

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

 /*
  * Copyright (C) 2008, 2011 Apple 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 143 matching lines @@
     // The client needs to implement these in order to be aware of layout effects
     // like CSS transforms.
     virtual IntRect convertFromScrollbarToContainingWidget(const Scrollbar* scrollbar, const IntRect& scrollbarRect) const
     {
         return scrollbar->Widget::convertToContainingWidget(scrollbarRect);
     }
     virtual IntRect convertFromContainingWidgetToScrollbar(const Scrollbar* scrollbar, const IntRect& parentRect) const
     {
         return scrollbar->Widget::convertFromContainingWidget(parentRect);
     }
+    virtual FloatRect convertFromScrollbarToContainingWidget(const Scrollbar* scrollbar, const FloatRect& scrollbarRect) const
+    {
+        return scrollbar->Widget::convertToContainingWidget(scrollbarRect);
+    }
     virtual IntPoint convertFromScrollbarToContainingWidget(const Scrollbar* scrollbar, const IntPoint& scrollbarPoint) const
     {
         return scrollbar->Widget::convertToContainingWidget(scrollbarPoint);
     }
     virtual IntPoint convertFromContainingWidgetToScrollbar(const Scrollbar* scrollbar, const IntPoint& parentPoint) const
     {
         return scrollbar->Widget::convertFromContainingWidget(parentPoint);
     }
 
     virtual Scrollbar* horizontalScrollbar() const { return 0; }
@@ skipping 171 matching lines @@
     // vertical-lr / ltr            NO                      NO
     // vertical-lr / rtl            NO                      YES
     // vertical-rl / ltr            YES                     NO
     // vertical-rl / rtl            YES                     YES
     IntPoint m_scrollOrigin;
 };
 
 } // namespace blink
 
 #endif // ScrollableArea_h