Introduce enum class TextAffinity as replacement of enum EAffinity

Source/core/layout/LayoutBlock.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 1805 matching lines @@
 
     // If we can't find an ancestor to check editability on, or editability is unchanged, we recur like normal
     if (isEditingBoundary(ancestor, child))
         return child->positionForPoint(pointInChildCoordinates);
 
     // Otherwise return before or after the child, depending on if the click was to the logical left or logical right of the child
     LayoutUnit childMiddle = parent->logicalWidthForChild(*child) / 2;
     LayoutUnit logicalLeft = parent->isHorizontalWritingMode() ? pointInChildCoordinates.x() : pointInChildCoordinates.y();
     if (logicalLeft < childMiddle)
         return ancestor->createPositionWithAffinity(childNode->nodeIndex());
-    return ancestor->createPositionWithAffinity(childNode->nodeIndex() + 1, UPSTREAM);
+    return ancestor->createPositionWithAffinity(childNode->nodeIndex() + 1, TextAffinity::Upstream);
 }
 
 PositionWithAffinity LayoutBlock::positionForPointWithInlineChildren(const LayoutPoint& pointInLogicalContents)
 {
     ASSERT(childrenInline());
 
     if (!firstRootBox())
         return createPositionWithAffinity(0);
 
     bool linesAreFlipped = style()->isFlippedLinesWritingMode();
@@ skipping 1081 matching lines @@
 void LayoutBlock::showLineTreeAndMark(const InlineBox* markedBox1, const char* markedLabel1, const InlineBox* markedBox2, const char* markedLabel2, const LayoutObject* obj) const
 {
     showLayoutObject();
     for (const RootInlineBox* root = firstRootBox(); root; root = root->nextRootBox())
         root->showLineTreeAndMark(markedBox1, markedLabel1, markedBox2, markedLabel2, obj, 1);
 }
 
 #endif
 
 } // namespace blink