Use float for scroll offset.

third_party/WebKit/Source/core/frame/LocalFrame.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Simon Hausmann <hausmann@kde.org>
  *                     2000 Stefan Schimanski <1Stein@gmx.de>
  *                     2001 George Staikos <staikos@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2005 Alexey Proskuryakov <ap@nypop.com>
@@ skipping 619 matching lines @@
   // WG clarification.
   if (document->isSVGDocument()) {
     if (!document->accessSVGExtensions().zoomAndPanEnabled())
       return;
   }
 
   if (m_pageZoomFactor != pageZoomFactor) {
     if (FrameView* view = this->view()) {
       // Update the scroll position when doing a full page zoom, so the content
       // stays in relatively the same position.
-      LayoutPoint scrollPosition = view->scrollPosition();
+      ScrollOffset scrollOffset = view->scrollOffset();
       float percentDifference = (pageZoomFactor / m_pageZoomFactor);
-      view->setScrollPosition(
-          DoublePoint(scrollPosition.x() * percentDifference,
-                      scrollPosition.y() * percentDifference),
+      view->setScrollOffset(
+          ScrollOffset(scrollOffset.width() * percentDifference,
+                       scrollOffset.height() * percentDifference),
           ProgrammaticScroll);
     }
   }
 
   m_pageZoomFactor = pageZoomFactor;
   m_textZoomFactor = textZoomFactor;
 
   for (Frame* child = tree().firstChild(); child;
        child = child->tree().nextSibling()) {
     if (child->isLocalFrame())
@@ skipping 243 matching lines @@
   if (m_frame && m_frame->client() && m_frame->client()->frameBlameContext())
     m_frame->client()->frameBlameContext()->Enter();
 }
 
 ScopedFrameBlamer::~ScopedFrameBlamer() {
   if (m_frame && m_frame->client() && m_frame->client()->frameBlameContext())
     m_frame->client()->frameBlameContext()->Leave();
 }
 
 }  // namespace blink