[NaCl SDK] Consistent use of copyright header.

native_client_sdk/src/examples/api/graphics_3d/matrix.cc

-/* Copyright (c) 2012 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.
- */
+// Copyright (c) 2012 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.
 
 /** @file matrix.cc
  * Implements simple matrix manipulation functions.
  */
 
 //-----------------------------------------------------------------------------
 #include <stdlib.h>
 #include <string.h>
 #include "matrix.h"
 #define deg_to_rad(x) (x * (M_PI / 180.0f))
@@ skipping 116 matching lines @@
   multiply_matrix(y_matrix, x_matrix, xy_matrix);
   multiply_matrix(z_matrix, xy_matrix, mat);
 }
 
 void translate_matrix(GLfloat x, GLfloat y, GLfloat z, Matrix_t mat) {
   identity_matrix(mat);
   mat[12] += x;
   mat[13] += y;
   mat[14] += z;
 }