Implement basic interfaces and attributes for DOMMatrix.

Source/core/dom/DOMMatrixReadOnly.cpp

Index: Source/core/dom/DOMMatrixReadOnly.cpp
diff --git a/Source/core/dom/DOMMatrixReadOnly.cpp b/Source/core/dom/DOMMatrixReadOnly.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..c710c01c0b870b2788980f86f57d30033c20ca6b
--- /dev/null
+++ b/Source/core/dom/DOMMatrixReadOnly.cpp
@@ -0,0 +1,25 @@
+// 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.
+
+#include "config.h"
+#include "core/dom/DOMMatrixReadOnly.h"
+
+namespace blink {
+
+bool DOMMatrixReadOnly::is2D() const
+{
+    return m31() == 0 && m32() == 0 && m13() == 0 && m23() == 0
+        && m43() == 0 && m14() == 0 && m24() == 0 && m34() == 0
+        && m33() == 1 && m44() == 1;

[Rik, 2014/08/01 17:26:46]

2D'ness of the matrix depends on how it was initialized and used.
So, 3D should become true if you use one of the 3D methods.

see: http://dev.w3.org/fxtf/geometry/#dom-dommatrixreadonly-is2d

[zino, 2014/08/02 02:24:53]

Done.

+}
+
+bool DOMMatrixReadOnly::isIdentity() const
+{
+    return m11() == 1 && m21() == 0 && m31() == 0 && m41() == 0
+        && m12() == 0 && m22() == 1 && m32() == 0 && m42() == 0
+        && m13() == 0 && m23() == 0 && m33() == 1 && m43() == 0
+        && m14() == 0 && m24() == 0 && m34() == 0 && m44() == 1;
+}
+
+} // namespace blink