Preserve fractional scroll offset for JS scrolling API

Source/core/dom/Element.cpp

Index: Source/core/dom/Element.cpp
diff --git a/Source/core/dom/Element.cpp b/Source/core/dom/Element.cpp
index 008fb9055e6258dde22c6474eb0809919eb8d8ec..a3807aec2b78bdc81ec01a43bcb432c81df92be3 100644
--- a/Source/core/dom/Element.cpp
+++ b/Source/core/dom/Element.cpp
@@ -680,7 +680,7 @@ void Element::setScrollLeft(double newLeft)
         if (!view)
             return;
 
-        view->setScrollPosition(IntPoint(roundf(newLeft * frame->pageZoomFactor()), view->scrollY()));
+        view->setScrollPosition(DoublePoint(newLeft * frame->pageZoomFactor(), view->scrollY()));
     }
 }
 
@@ -727,7 +727,7 @@ void Element::setScrollTop(double newTop)
         if (!view)
             return;
 
-        view->setScrollPosition(IntPoint(view->scrollX(), roundf(newTop * frame->pageZoomFactor())));
+        view->setScrollPosition(DoublePoint(view->scrollX(), newTop * frame->pageZoomFactor()));
     }
 }