Use float for scroll offset.

third_party/WebKit/Source/core/style/ComputedStyle.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 3994 matching lines @@
 inline double adjustDoubleForAbsoluteZoom(double value,
                                           const ComputedStyle& style) {
   return value / style.effectiveZoom();
 }
 
 inline LayoutUnit adjustLayoutUnitForAbsoluteZoom(LayoutUnit value,
                                                   const ComputedStyle& style) {
   return LayoutUnit(value / style.effectiveZoom());
 }
 
-inline double adjustScrollForAbsoluteZoom(double scrollOffset,
-                                          float zoomFactor) {
+inline float adjustScrollForAbsoluteZoom(float scrollOffset, float zoomFactor) {
   return scrollOffset / zoomFactor;
 }
 
-inline double adjustScrollForAbsoluteZoom(double scrollOffset,
-                                          const ComputedStyle& style) {
+inline float adjustScrollForAbsoluteZoom(float scrollOffset,
+                                         const ComputedStyle& style) {
   return adjustScrollForAbsoluteZoom(scrollOffset, style.effectiveZoom());
 }
 
 inline bool ComputedStyle::setZoom(float f) {
   if (compareEqual(m_visual->m_zoom, f))
     return false;
   m_visual.access()->m_zoom = f;
   setEffectiveZoom(effectiveZoom() * zoom());
   return true;
 }
@@ skipping 40 matching lines @@
   m_nonInheritedData.m_pseudoBits |= 1 << (pseudo - 1);
 }
 
 inline bool ComputedStyle::hasPseudoElementStyle() const {
   return m_nonInheritedData.m_pseudoBits & ElementPseudoIdMask;
 }
 
 }  // namespace blink
 
 #endif  // ComputedStyle_h