Implement scale*() methods in 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 {
@@ skipping 20 matching lines @@
     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;
 
+    DOMMatrix* scale(double scale, double ox = 0, double oy = 0);
+    DOMMatrix* scale3d(double scale, double ox = 0, double oy = 0, double oz = 0);
+    DOMMatrix* scaleNonUniform(double sx, double sy = 1, double sz = 1,
+        double ox = 0, double oy = 0, double oz = 0);
+
     void trace(Visitor*) { }
 
 protected:
     double m_matrix[4][4];
     bool m_is2D;
 };
 
 } // namespace blink
 
 #endif