Use float for scroll offset.

third_party/WebKit/Source/web/WebViewImpl.cpp

Index: third_party/WebKit/Source/web/WebViewImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebViewImpl.cpp b/third_party/WebKit/Source/web/WebViewImpl.cpp
index 3ce96f9ad006087364986b5c9a1798856ca3bb94..9372c08095d699c302c696f9fabe32045a584f14 100644
--- a/third_party/WebKit/Source/web/WebViewImpl.cpp
+++ b/third_party/WebKit/Source/web/WebViewImpl.cpp
@@ -1020,9 +1020,10 @@ bool WebViewImpl::startPageScaleAnimation(const IntPoint& targetPosition,
       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;
     }
@@ -3368,7 +3369,7 @@ void WebViewImpl::scrollAndRescaleViewports(
   // 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);
 
@@ -3679,9 +3680,8 @@ void WebViewImpl::resetScrollAndScaleState() {
   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);