Introduce enum class TextAffinity as replacement of enum EAffinity

Source/core/editing/commands/TypingCommand.cpp

Index: Source/core/editing/commands/TypingCommand.cpp
diff --git a/Source/core/editing/commands/TypingCommand.cpp b/Source/core/editing/commands/TypingCommand.cpp
index 4c20d85a998c3dfdda938e88ea1c776232ae4947..f9b70e6c809f016e17fa59c793496772bbeecb14 100644
--- a/Source/core/editing/commands/TypingCommand.cpp
+++ b/Source/core/editing/commands/TypingCommand.cpp
@@ -402,7 +402,7 @@ bool TypingCommand::makeEditableRootEmpty()
         removeNode(child);
 
     addBlockPlaceholderIfNeeded(root);
-    setEndingSelection(VisibleSelection(firstPositionInNode(root), DOWNSTREAM, endingSelection().isDirectional()));
+    setEndingSelection(VisibleSelection(firstPositionInNode(root), TextAffinity::Downstream, endingSelection().isDirectional()));
 
     return true;
 }
@@ -465,7 +465,7 @@ void TypingCommand::deleteKeyPressed(TextGranularity granularity, bool killRing)
             selection->modify(FrameSelection::AlterationExtend, DirectionBackward, granularity);
         // If the caret is just after a table, select the table and don't delete anything.
         } else if (Element* table = isFirstPositionAfterTable(visibleStart)) {
-            setEndingSelection(VisibleSelection(positionBeforeNode(table), endingSelection().start(), DOWNSTREAM, endingSelection().isDirectional()));
+            setEndingSelection(VisibleSelection(positionBeforeNode(table), endingSelection().start(), TextAffinity::Downstream, endingSelection().isDirectional()));
             typingAddedToOpenCommand(DeleteKey);
             return;
         }
@@ -549,7 +549,7 @@ void TypingCommand::forwardDeleteKeyPressed(TextGranularity granularity, bool ki
             downstreamEnd = visibleEnd.next(CannotCrossEditingBoundary).deepEquivalent().downstream();
         // When deleting tables: Select the table first, then perform the deletion
         if (isRenderedTableElement(downstreamEnd.computeContainerNode()) && downstreamEnd.computeOffsetInContainerNode() <= caretMinOffset(downstreamEnd.computeContainerNode())) {
-            setEndingSelection(VisibleSelection(endingSelection().end(), positionAfterNode(downstreamEnd.computeContainerNode()), DOWNSTREAM, endingSelection().isDirectional()));
+            setEndingSelection(VisibleSelection(endingSelection().end(), positionAfterNode(downstreamEnd.computeContainerNode()), TextAffinity::Downstream, endingSelection().isDirectional()));
             typingAddedToOpenCommand(ForwardDeleteKey);
             return;
         }