Implement basic interfaces and attributes for DOMMatrix.

Source/core/dom/DOMMatrixReadOnly.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 DOMMatrixReadOnly_h
+#define DOMMatrixReadOnly_h
+
+#include "platform/heap/Handle.h"
+
+namespace blink {
+
+class DOMMatrixReadOnly : public GarbageCollected<DOMMatrixReadOnly> {
+public:
+    double a() const { return m11(); }
+    double b() const { return m12(); }
+    double c() const { return m21(); }
+    double d() const { return m22(); }
+    double e() const { return m41(); }
+    double f() const { return m42(); }
+
+    double m11() const { return m_matrix[0][0]; }
+    double m12() const { return m_matrix[0][1]; }
+    double m13() const { return m_matrix[0][2]; }
+    double m14() const { return m_matrix[0][3]; }
+    double m21() const { return m_matrix[1][0]; }
+    double m22() const { return m_matrix[1][1]; }
+    double m23() const { return m_matrix[1][2]; }
+    double m24() const { return m_matrix[1][3]; }
+    double m31() const { return m_matrix[2][0]; }
+    double m32() const { return m_matrix[2][1]; }
+    double m33() const { return m_matrix[2][2]; }
+    double m34() const { return m_matrix[2][3]; }
+    double m41() const { return m_matrix[3][0]; }
+    double m42() const { return m_matrix[3][1]; }
+    double m43() const { return m_matrix[3][2]; }
+    double m44() const { return m_matrix[3][3]; }
+
+    bool is2D() const;
+    bool isIdentity() const;
+
+    void trace(Visitor*) { }
+
+protected:
+    double m_matrix[4][4];
+    bool m_is2D;
+};
+
+} // namespace blink
+
+#endif