Use float for scroll offset.

third_party/WebKit/Source/core/dom/Element.h

Index: third_party/WebKit/Source/core/dom/Element.h
diff --git a/third_party/WebKit/Source/core/dom/Element.h b/third_party/WebKit/Source/core/dom/Element.h
index 70e467451c0ec99b65c54e432882c5d4ed8d63e1..ca5a3767e8c54caa125b89ab2a50766a8619a420 100644
--- a/third_party/WebKit/Source/core/dom/Element.h
+++ b/third_party/WebKit/Source/core/dom/Element.h
@@ -38,6 +38,7 @@
 #include "core/dom/SpaceSplitString.h"
 #include "core/html/CollectionType.h"
 #include "platform/heap/Handle.h"
+#include "platform/scroll/ScrollTypes.h"
 #include "public/platform/WebFocusType.h"
 
 namespace blink {
@@ -654,8 +655,8 @@ class CORE_EXPORT Element : public ContainerNode {
   bool hasClass() const;
   const SpaceSplitString& classNames() const;
 
-  IntSize savedLayerScrollOffset() const;
-  void setSavedLayerScrollOffset(const IntSize&);
+  ScrollOffset savedLayerScrollOffset() const;
+  void setSavedLayerScrollOffset(const ScrollOffset&);
 
   ElementAnimations* elementAnimations() const;
   ElementAnimations& ensureElementAnimations();