Use float for scroll offset.

third_party/WebKit/Source/web/WebHistoryItem.cpp

 /*
  * Copyright (C) 2009 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 69 matching lines @@
 
 WebString WebHistoryItem::target() const {
   return m_private->target();
 }
 
 void WebHistoryItem::setTarget(const WebString& target) {
   m_private->setTarget(target);
 }
 
 WebFloatPoint WebHistoryItem::visualViewportScrollOffset() const {
-  return m_private->visualViewportScrollPoint();
+  ScrollOffset offset = m_private->visualViewportScrollOffset();
+  return WebFloatPoint(offset.width(), offset.height());
 }
 
 void WebHistoryItem::setVisualViewportScrollOffset(
     const WebFloatPoint& scrollOffset) {
-  m_private->setVisualViewportScrollPoint(scrollOffset);
+  m_private->setVisualViewportScrollOffset(toScrollOffset(scrollOffset));
 }
 
 WebPoint WebHistoryItem::scrollOffset() const {
-  return m_private->scrollPoint();
+  ScrollOffset offset = m_private->scrollOffset();
+  return WebPoint(offset.width(), offset.height());
 }
 
 void WebHistoryItem::setScrollOffset(const WebPoint& scrollOffset) {
-  m_private->setScrollPoint(scrollOffset);
+  m_private->setScrollOffset(ScrollOffset(scrollOffset.x, scrollOffset.y));
 }
 
 float WebHistoryItem::pageScaleFactor() const {
   return m_private->pageScaleFactor();
 }
 
 void WebHistoryItem::setPageScaleFactor(float scale) {
   m_private->setPageScaleFactor(scale);
 }
 
@@ skipping 87 matching lines @@
 WebHistoryItem& WebHistoryItem::operator=(HistoryItem* item) {
   m_private = item;
   return *this;
 }
 
 WebHistoryItem::operator HistoryItem*() const {
   return m_private.get();
 }
 
 }  // namespace blink