Fix scrollWidth/Height to not truncate scroll offset

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 e6bba982e9fc9f426a917e20b62ae5f873d9c100..6785eb9b84ecb55bf4b158dd829506a66d4a42c3 100644
--- a/Source/core/dom/Element.cpp
+++ b/Source/core/dom/Element.cpp
@@ -804,7 +804,7 @@ double Element::scrollWidth()
 {
     document().updateLayoutIgnorePendingStylesheets();
     if (RenderBox* rend = renderBox())
-        return adjustForAbsoluteZoom(rend->scrollWidth(), rend);
+        return adjustLayoutUnitForAbsoluteZoom(rend->scrollWidth(), *rend).toDouble();
     return 0;
 }
 
@@ -812,7 +812,7 @@ double Element::scrollHeight()
 {
     document().updateLayoutIgnorePendingStylesheets();
     if (RenderBox* rend = renderBox())
-        return adjustForAbsoluteZoom(rend->scrollHeight(), rend);
+        return adjustLayoutUnitForAbsoluteZoom(rend->scrollHeight(), *rend).toDouble();
     return 0;
 }