Implement DOMRect of geometry interfaces.

Source/core/dom/DOMRectReadOnly.h

+// 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 DOMRectReadOnly_h
+#define DOMRectReadOnly_h
+
+#include "platform/heap/Handle.h"
+
+namespace WebCore {
+
+class DOMRectReadOnly : public GarbageCollected<DOMRectReadOnly> {
+public:
+    static DOMRectReadOnly* create(double x, double y, double width, double height);
+
+    double x() const { return m_x; }
+    double y() const { return m_y; }
+    double width() const { return m_width; }
+    double height() const { return m_height; }
+
+    double top() const { return std::min(m_y, m_y + m_height); }
+    double right() const { return std::max(m_x, m_x + m_width); }
+    double bottom() const { return std::max(m_y, m_y + m_height); }
+    double left() const { return std::min(m_x, m_x + m_width); }
+
+    void trace(Visitor*) { }
+
+protected:
+    DOMRectReadOnly(double x, double y, double width, double height);
+
+    double m_x;
+    double m_y;
+    double m_width;
+    double m_height;
+};
+
+} // namespace WebCore
+
+#endif