Add ScrollDirectionPhysical enum in Scroll types.

Source/core/layout/LayoutBox.cpp

Index: Source/core/layout/LayoutBox.cpp
diff --git a/Source/core/layout/LayoutBox.cpp b/Source/core/layout/LayoutBox.cpp
index 2b7d8514f1bf07338b2292b26e9487480019bd5c..f4b5ff67df569b6250840ac1dd48358e8ad7309d 100644
--- a/Source/core/layout/LayoutBox.cpp
+++ b/Source/core/layout/LayoutBox.cpp
@@ -711,14 +711,11 @@ int LayoutBox::intrinsicScrollbarLogicalWidth() const
     return 0;
 }
 
-bool LayoutBox::scroll(ScrollDirection direction, ScrollGranularity granularity, float delta)
+bool LayoutBox::scroll(ScrollDirectionPhysical direction, ScrollGranularity granularity, float delta)
 {
     // Presumably the same issue as in setScrollTop. See crbug.com/343132.
     DisableCompositingQueryAsserts disabler;
 
-    // Logical scroll is a higher level concept, all directions by here must be physical
-    ASSERT(!isLogical(direction));
-
     if (!layer() || !layer()->scrollableArea())
         return false;