Avoid uninitialized memory when decomposing a matrix fails.

Source/platform/transforms/TransformationMatrix.h

 /*
  * Copyright (C) 2005, 2006 Apple Computer, 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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 236 matching lines @@
 
     // decompose the matrix into its component parts
     typedef struct {
         double scaleX, scaleY, scaleZ;
         double skewXY, skewXZ, skewYZ;
         double quaternionX, quaternionY, quaternionZ, quaternionW;
         double translateX, translateY, translateZ;
         double perspectiveX, perspectiveY, perspectiveZ, perspectiveW;
     } DecomposedType;
 
-    bool decompose(DecomposedType& decomp) const;
-    void recompose(const DecomposedType& decomp);
+    bool decompose(DecomposedType&) const WARN_UNUSED_RETURN;
+    void recompose(const DecomposedType&);
 
     void blend(const TransformationMatrix& from, double progress);
 
     bool isAffine() const
     {
         return (m13() == 0 && m14() == 0 && m23() == 0 && m24() == 0 &&
                 m31() == 0 && m32() == 0 && m33() == 1 && m34() == 0 && m43() == 0 && m44() == 1);
     }
 
     // Throw away the non-affine parts of the matrix (lossy!)
@@ skipping 91 matching lines @@
         if (m && m != m_matrix)
             memcpy(m_matrix, m, sizeof(Matrix4));
     }
 
     Matrix4 m_matrix;
 };
 
 } // namespace blink
 
 #endif // TransformationMatrix_h