Introduce enum class TextAffinity as replacement of enum EAffinity

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 43e4c1473d36db47b55150a09043360af952d63d..2a832e6b38a72cb2377da68f3446285ab08ee30b 100644
--- a/Source/core/dom/Element.cpp
+++ b/Source/core/dom/Element.cpp
@@ -2329,7 +2329,7 @@ void Element::updateFocusAppearance(bool /*restorePreviousSelection*/)
             return;
 
         // FIXME: We should restore the previous selection if there is one.
-        VisibleSelection newSelection = VisibleSelection(firstPositionInOrBeforeNode(this), DOWNSTREAM);
+        VisibleSelection newSelection = VisibleSelection(firstPositionInOrBeforeNode(this), TextAffinity::Downstream);
         // Passing DoNotSetFocus as this function is called after FocusController::setFocusedElement()
         // and we don't want to change the focus to a new Element.
         frame->selection().setSelection(newSelection,  FrameSelection::CloseTyping | FrameSelection::ClearTypingStyle | FrameSelection::DoNotSetFocus);