Add copyright headers to remaining gyp files.
Prevents some PRESUBMIT errors.
TBR=mtklein@google.com
Review URL: https://codereview.chromium.org/1035523003
diff --git a/gyp/gmslides.gypi b/gyp/gmslides.gypi
index ab0a2b3..8effe7f 100644
--- a/gyp/gmslides.gypi
+++ b/gyp/gmslides.gypi
@@ -1,3 +1,7 @@
+# Copyright 2015 Google Inc.
+#
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
# include this gypi to include all the golden master slides.
{
'include_dirs': [