Fix licenses in headers to pass Chromium's checklicenses tool.

This is a re-landing of the changes in https://pdfium.googlesource.com/pdfium/+/6387aff
which were lost during a libopenjpeg library roll.

TBR=thestig@chromium.org

Review URL: https://codereview.chromium.org/661463003
diff --git a/core/src/fxcodec/fx_libopenjpeg/libopenjpeg20/opj_config.h b/core/src/fxcodec/fx_libopenjpeg/libopenjpeg20/opj_config.h
index 9f4bb0f..37bc9ba 100644
--- a/core/src/fxcodec/fx_libopenjpeg/libopenjpeg20/opj_config.h
+++ b/core/src/fxcodec/fx_libopenjpeg/libopenjpeg20/opj_config.h
@@ -1,3 +1,9 @@
+// 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
+
 /* create opj_config.h for CMake */
 #define OPJ_HAVE_STDINT_H 		1
 
diff --git a/core/src/fxcodec/fx_libopenjpeg/libopenjpeg20/opj_config_private.h b/core/src/fxcodec/fx_libopenjpeg/libopenjpeg20/opj_config_private.h
index 5a6c33d..7d7e3ea 100644
--- a/core/src/fxcodec/fx_libopenjpeg/libopenjpeg20/opj_config_private.h
+++ b/core/src/fxcodec/fx_libopenjpeg/libopenjpeg20/opj_config_private.h
@@ -1,3 +1,9 @@
+// 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
+
 /* create opj_config_private.h for CMake */
 #define OPJ_HAVE_INTTYPES_H 	1