Move PositionWithAffinity class to editing

Source/core/editing/PositionWithAffinity.h

Index: Source/core/editing/PositionWithAffinity.h
diff --git a/Source/core/editing/PositionWithAffinity.h b/Source/core/editing/PositionWithAffinity.h
new file mode 100644
index 0000000000000000000000000000000000000000..8cb401cdadcca3a5c5f65cedf03421d7cd212d9e
--- /dev/null
+++ b/Source/core/editing/PositionWithAffinity.h
@@ -0,0 +1,32 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file./*
+
+#ifndef PositionWithAffinity_h
+#define PositionWithAffinity_h
+
+#include "core/dom/Position.h"
+#include "core/editing/TextAffinity.h"
+
+namespace WebCore {
+
+class PositionWithAffinity {
+    DISALLOW_ALLOCATION();
+public:
+    PositionWithAffinity(const Position&, EAffinity = DOWNSTREAM);
+    PositionWithAffinity();
+    ~PositionWithAffinity();
+
+    EAffinity affinity() const { return m_affinity; }
+    const Position& position() const { return m_position; }
+
+    void trace(Visitor*);
+
+private:
+    Position m_position;
+    EAffinity m_affinity;
+};
+
+} // namespace WebCore
+
+#endif // PositionWithAffinity_h