Add ScrollDirectionPhysical enum in Scroll types.

Source/core/page/EventHandler.cpp

Index: Source/core/page/EventHandler.cpp
diff --git a/Source/core/page/EventHandler.cpp b/Source/core/page/EventHandler.cpp
index d26cd614a18903911ad11f4746158ee73bb540f4..be71ef73b40fa8580b11558f8c0293949443cb6b 100644
--- a/Source/core/page/EventHandler.cpp
+++ b/Source/core/page/EventHandler.cpp
@@ -942,7 +942,7 @@ bool EventHandler::scroll(ScrollDirection direction, ScrollGranularity granulari
 
     LayoutBox* curBox = node->layoutObject()->enclosingBox();
     while (curBox && !curBox->isLayoutView()) {
-        ScrollDirection physicalDirection = toPhysicalDirection(
+        ScrollDirectionPhysical physicalDirection = toPhysicalDirection(
             direction, curBox->isHorizontalWritingMode(), curBox->style()->isFlippedBlocksWritingMode());
 
         // If we're at the stopNode, we should try to scroll it but we shouldn't bubble past it
@@ -984,7 +984,9 @@ bool EventHandler::bubblingScroll(ScrollDirection direction, ScrollGranularity g
         return true;
     LocalFrame* frame = m_frame;
     FrameView* view = frame->view();
-    if (view && view->scrollableArea()->scroll(direction, granularity)) {
+    ScrollDirectionPhysical physicalDirection =
+        toPhysicalDirection(direction, view->isVerticalDocument(), view->isFlippedDocument());
+    if (view && view->scrollableArea()->scroll(physicalDirection, granularity)) {
         setFrameWasScrolledByUser();
         return true;
     }
@@ -3650,7 +3652,7 @@ void EventHandler::defaultSpaceEventHandler(KeyboardEvent* event)
     if (!view)
         return;
 
-    ScrollDirection physicalDirection =
+    ScrollDirectionPhysical physicalDirection =
         toPhysicalDirection(direction, view->isVerticalDocument(), view->isFlippedDocument());
 
     if (view->scrollableArea()->scroll(physicalDirection, ScrollByPage))