Add localToAbsoluteTransform and localToAncestorTransform.

third_party/WebKit/Source/platform/transforms/TransformationMatrix.cpp

 /*
  * Copyright (C) 2005, 2006 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) 2009 Torch Mobile, Inc.
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 1380 matching lines @@
     m_matrix[3][2] = 0;
     m_matrix[3][3] = 1;
 }
 
 AffineTransform TransformationMatrix::toAffineTransform() const
 {
     return AffineTransform(m_matrix[0][0], m_matrix[0][1], m_matrix[1][0],
                            m_matrix[1][1], m_matrix[3][0], m_matrix[3][1]);
 }
 
+void TransformationMatrix::flattenTo2d()
+{
+    m_matrix[2][0] = 0;
+    m_matrix[2][1] = 0;
+    m_matrix[0][2] = 0;
+    m_matrix[1][2] = 0;
+    m_matrix[2][2] = 1;
+    m_matrix[3][2] = 0;
+    m_matrix[2][3] = 0;
+}
+
 static inline void blendFloat(double& from, double to, double progress)
 {
     if (from != to)
         from = from + (to - from) * progress;
 }
 
 void TransformationMatrix::blend(const TransformationMatrix& from, double progress)
 {
     if (from.isIdentity() && isIdentity())
         return;
@@ skipping 156 matching lines @@
     ret.setDouble(2, 2, matrix.m33());
     ret.setDouble(2, 3, matrix.m43());
     ret.setDouble(3, 0, matrix.m14());
     ret.setDouble(3, 1, matrix.m24());
     ret.setDouble(3, 2, matrix.m34());
     ret.setDouble(3, 3, matrix.m44());
     return ret;
 }
 
 } // namespace blink