Fix accidental deletion from commit 60cd033a.

Put the first two lines of the copyright header back in.

Change-Id: I1136417a16d2d03f150fa47aa9764f51a5011d65
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/56190
Commit-Queue: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>

fxbarcode/datamatrix/BC_TextEncoder.cpp

diff --git a/fxbarcode/datamatrix/BC_TextEncoder.cpp b/fxbarcode/datamatrix/BC_TextEncoder.cpp
index 8fcdb6f..bf87afa 100644
--- a/fxbarcode/datamatrix/BC_TextEncoder.cpp
+++ b/fxbarcode/datamatrix/BC_TextEncoder.cpp
@@ -1,3 +1,5 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com