[Alignment] Single class for holding the alignment data.

Source/core/style/StyleSelfAlignmentData.h

+// Copyright (c) 2015 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 StyleSelfAlignmentData_h
+#define StyleSelfAlignmentData_h
+
+#include "core/style/ComputedStyleConstants.h"
+
+namespace blink {
+
+class StyleSelfAlignmentData {
+public:
+    // Style data for Self-Aligment and Default-Alignment properties: align-{self, items}, justify-{self, items}.
+    // [ <self-position> && <overflow-position>? ] | [ legacy && [ left | right | center ] ]
+    StyleSelfAlignmentData(ItemPosition position, OverflowAlignment overflow, ItemPositionType positionType = NonLegacyPosition)
+        : m_position(position)
+        , m_positionType(positionType)
+        , m_overflow(overflow)
+    {
+    }
+
+    void setPosition(ItemPosition position) { m_position = position; }
+    void setPositionType(ItemPositionType positionType) { m_positionType = positionType; }
+    void setOverflow(OverflowAlignment overflow) { m_overflow = overflow; }
+
+    ItemPosition position() const { return static_cast<ItemPosition>(m_position); }
+    ItemPositionType positionType() const { return static_cast<ItemPositionType>(m_positionType); }
+    OverflowAlignment overflow() const { return static_cast<OverflowAlignment>(m_overflow); }
+
+    bool operator==(const StyleSelfAlignmentData& o) const
+    {
+        return m_position == o.m_position && m_positionType == o.m_positionType && m_overflow == o.m_overflow;
+    }
+
+    bool operator!=(const StyleSelfAlignmentData& o) const
+    {
+        return !(*this == o);
+    }
+
+private:
+    unsigned m_position : 4; // ItemPosition
+    unsigned m_positionType: 1; // Whether or not alignment uses the 'legacy' keyword.
+    unsigned m_overflow : 2; // OverflowAlignment
+};
+
+} // namespace blink
+
+#endif // StyleSelfAlignmentData_h