Use float for scroll offset.

third_party/WebKit/Source/core/loader/HistoryItem.h

Index: third_party/WebKit/Source/core/loader/HistoryItem.h
diff --git a/third_party/WebKit/Source/core/loader/HistoryItem.h b/third_party/WebKit/Source/core/loader/HistoryItem.h
index 6c68b3318ac2cdf99fc168ad1491028a8019ac07..cde3bbf85667b261e2e95da89a9f9d7774bb7aa7 100644
--- a/third_party/WebKit/Source/core/loader/HistoryItem.h
+++ b/third_party/WebKit/Source/core/loader/HistoryItem.h
@@ -33,6 +33,7 @@
 #include "platform/geometry/FloatPoint.h"
 #include "platform/geometry/IntPoint.h"
 #include "platform/heap/Handle.h"
+#include "platform/scroll/ScrollTypes.h"
 #include "platform/weborigin/Referrer.h"
 #include "wtf/text/WTFString.h"
 
@@ -59,10 +60,10 @@ class CORE_EXPORT HistoryItem final
   EncodedFormData* formData();
   const AtomicString& formContentType() const;
 
-  const FloatPoint& visualViewportScrollPoint() const;
-  void setVisualViewportScrollPoint(const FloatPoint&);
-  const IntPoint& scrollPoint() const;
-  void setScrollPoint(const IntPoint&);
+  const ScrollOffset& visualViewportScrollOffset() const;
+  void setVisualViewportScrollOffset(const ScrollOffset&);
+  const ScrollOffset& scrollOffset() const;
+  void setScrollOffset(const ScrollOffset&);
 
   float pageScaleFactor() const;
   void setPageScaleFactor(float);
@@ -113,8 +114,8 @@ class CORE_EXPORT HistoryItem final
   Referrer m_referrer;
   String m_target;
 
-  FloatPoint m_visualViewportScrollPoint;
-  IntPoint m_scrollPoint;
+  ScrollOffset m_visualViewportScrollOffset;
+  ScrollOffset m_scrollOffset;
   float m_pageScaleFactor;
   Vector<String> m_documentStateVector;
   Member<DocumentState> m_documentState;