Move the test template to //testing/test.gni (part 1)

This is the first CL to move the test template to //testing/test.gni

This CL is just creating an empty test.gni file. It is needed because
the test template is used in Blink, so we need to makes this change in
stages.

[email protected]

Review URL: https://codereview.chromium.org/850743003

Cr-Commit-Position: refs/heads/master@{#311341}
diff --git a/testing/test.gni b/testing/test.gni
new file mode 100644
index 0000000..50b23df
--- /dev/null
+++ b/testing/test.gni
@@ -0,0 +1,3 @@
+# Copyright 2015 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.