Use float for scroll offset.

third_party/WebKit/Source/web/WebViewImpl.cpp

 /*
  * Copyright (C) 2011, 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 1002 matching lines @@
                                           double durationInSeconds) {
   VisualViewport& visualViewport = page()->frameHost().visualViewport();
   WebPoint clampedPoint = targetPosition;
   if (!useAnchor) {
     clampedPoint =
         visualViewport.clampDocumentOffsetAtScale(targetPosition, newScale);
     if (!durationInSeconds) {
       setPageScaleFactor(newScale);
 
       FrameView* view = mainFrameImpl()->frameView();
-      if (view && view->getScrollableArea())
-        view->getScrollableArea()->setScrollPosition(
-            DoublePoint(clampedPoint.x, clampedPoint.y), ProgrammaticScroll);
+      if (view && view->getScrollableArea()) {
+        view->getScrollableArea()->setScrollOffset(
+            ScrollOffset(clampedPoint.x, clampedPoint.y), ProgrammaticScroll);
+      }
 
       return false;
     }
   }
   if (useAnchor && newScale == pageScaleFactor())
     return false;
 
   if (m_enableFakePageScaleAnimationForTesting) {
     m_fakePageScaleAnimationTargetPosition = targetPosition;
     m_fakePageScaleAnimationUseAnchor = useAnchor;
@@ skipping 2325 matching lines @@
   if (!mainFrameImpl())
     return;
 
   FrameView* view = mainFrameImpl()->frameView();
   if (!view)
     return;
 
   // Order is important: visual viewport location is clamped based on
   // main frame scroll position and visual viewport scale.
 
-  view->setScrollPosition(mainFrameOrigin, ProgrammaticScroll);
+  view->setScrollOffset(toScrollOffset(mainFrameOrigin), ProgrammaticScroll);
 
   setPageScaleFactor(scaleFactor);
 
   page()->frameHost().visualViewport().setLocation(visualViewportOrigin);
 }
 
 void WebViewImpl::setPageScaleFactorAndLocation(float scaleFactor,
                                                 const FloatPoint& location) {
   DCHECK(page());
 
@@ skipping 290 matching lines @@
 
 void WebViewImpl::resetScrollAndScaleState() {
   page()->frameHost().visualViewport().reset();
 
   if (!page()->mainFrame()->isLocalFrame())
     return;
 
   if (FrameView* frameView = toLocalFrame(page()->mainFrame())->view()) {
     ScrollableArea* scrollableArea = frameView->layoutViewportScrollableArea();
 
-    if (scrollableArea->scrollPositionDouble() != DoublePoint::zero())
-      scrollableArea->setScrollPosition(DoublePoint::zero(),
-                                        ProgrammaticScroll);
+    if (!scrollableArea->scrollOffset().isZero())
+      scrollableArea->setScrollOffset(ScrollOffset(), ProgrammaticScroll);
   }
 
   pageScaleConstraintsSet().setNeedsReset(true);
 }
 
 void WebViewImpl::performMediaPlayerAction(const WebMediaPlayerAction& action,
                                            const WebPoint& location) {
   HitTestResult result = hitTestResultForViewportPos(location);
   Node* node = result.innerNode();
   if (!isHTMLVideoElement(*node) && !isHTMLAudioElement(*node))
@@ skipping 1001 matching lines @@
   if (focusedFrame->localFrameRoot() != mainFrameImpl()->frame())
     return nullptr;
   return focusedFrame;
 }
 
 LocalFrame* WebViewImpl::focusedLocalFrameAvailableForIme() const {
   return m_imeAcceptEvents ? focusedLocalFrameInWidget() : nullptr;
 }
 
 }  // namespace blink