Introduce enum class TextAffinity as replacement of enum EAffinity

Source/core/editing/FrameSelection.h

Index: Source/core/editing/FrameSelection.h
diff --git a/Source/core/editing/FrameSelection.h b/Source/core/editing/FrameSelection.h
index c060af9f951b71ef447c36cbd57d3bdf84a6f98c..f553b2ad814ecd8bd7756f9662e0d8d7d32aa5d2 100644
--- a/Source/core/editing/FrameSelection.h
+++ b/Source/core/editing/FrameSelection.h
@@ -103,15 +103,15 @@ public:
 
     void moveTo(const VisiblePosition&, EUserTriggered = NotUserTriggered, CursorAlignOnScroll = AlignCursorOnScrollIfNeeded);
     void moveTo(const VisiblePosition&, const VisiblePosition&, EUserTriggered = NotUserTriggered);
-    void moveTo(const Position&, EAffinity, EUserTriggered = NotUserTriggered);
+    void moveTo(const Position&, TextAffinity, EUserTriggered = NotUserTriggered);
 
     const VisibleSelection& selection() const { return m_selection; }
     void setSelection(const VisibleSelection&, SetSelectionOptions = CloseTyping | ClearTypingStyle, CursorAlignOnScroll = AlignCursorOnScrollIfNeeded, TextGranularity = CharacterGranularity);
     void setSelection(const VisibleSelection& selection, TextGranularity granularity) { setSelection(selection, CloseTyping | ClearTypingStyle, AlignCursorOnScrollIfNeeded, granularity); }
     // TODO(yosin) We should get rid of |Range| version of |setSelectedRagne()|
     // for Oilpan.
-    bool setSelectedRange(Range*, EAffinity, DirectionalOption = NonDirectional, SetSelectionOptions = CloseTyping | ClearTypingStyle);
-    bool setSelectedRange(const EphemeralRange&, EAffinity, DirectionalOption = NonDirectional, SetSelectionOptions = CloseTyping | ClearTypingStyle);
+    bool setSelectedRange(Range*, TextAffinity, DirectionalOption = NonDirectional, SetSelectionOptions = CloseTyping | ClearTypingStyle);
+    bool setSelectedRange(const EphemeralRange&, TextAffinity, DirectionalOption = NonDirectional, SetSelectionOptions = CloseTyping | ClearTypingStyle);
     void selectAll();
     void clear();
     void prepareForDestruction();
@@ -123,7 +123,7 @@ public:
 
     SelectionType selectionType() const { return m_selection.selectionType(); }
 
-    EAffinity affinity() const { return m_selection.affinity(); }
+    TextAffinity affinity() const { return m_selection.affinity(); }
 
     bool modify(EAlteration, SelectionDirection, TextGranularity, EUserTriggered = NotUserTriggered);
     enum VerticalDirection { DirectionUp, DirectionDown };