Use float for scroll offset.

third_party/WebKit/Source/core/paint/BackgroundImageGeometry.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/paint/BackgroundImageGeometry.h"
 
 #include "core/frame/FrameView.h"
 #include "core/layout/LayoutBox.h"
 #include "core/layout/LayoutBoxModelObject.h"
 #include "core/layout/LayoutView.h"
@@ skipping 367 matching lines @@
           paintRect.size() - LayoutSize(left + right, top + bottom);
     }
   } else {
     setHasNonLocalGeometry();
 
     LayoutRect viewportRect = obj.viewRect();
     if (fixedBackgroundPaintsInLocalCoordinates(obj, globalPaintFlags)) {
       viewportRect.setLocation(LayoutPoint());
     } else {
       if (FrameView* frameView = obj.view()->frameView())
-        viewportRect.setLocation(frameView->scrollPosition());
+        viewportRect.setLocation(IntPoint(frameView->scrollOffsetInt()));
       // Compensate the translations created by ScrollRecorders.
       // TODO(trchen): Fix this for SP phase 2. crbug.com/529963.
       viewportRect.moveBy(
           accumulatedScrollOffsetForFixedBackground(obj, paintContainer));
     }
 
     if (paintContainer)
       viewportRect.moveBy(
           LayoutPoint(-paintContainer->localToAbsolute(FloatPoint())));
 
@@ skipping 113 matching lines @@
     useFixedAttachment(paintRect.location());
 
   // Clip the final output rect to the paint rect
   m_destRect.intersect(paintRect);
 
   // Snap as-yet unsnapped values.
   setDestRect(LayoutRect(pixelSnappedIntRect(m_destRect)));
 }
 
 }  // namespace blink