SkMojo: test linking Skia against the Mojo SDK

TODO: build on systems other than Linux.

Add mojo_skd to the DEPS.

Add a DM::Via called `mojo-`.

everything is hidden behind the gyp variable `skia_mojo`.
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1644043003

Review URL: https://codereview.chromium.org/1644043003
diff --git a/experimental/mojo/SkMojo.mojom b/experimental/mojo/SkMojo.mojom
new file mode 100644
index 0000000..85b46cc
--- /dev/null
+++ b/experimental/mojo/SkMojo.mojom
@@ -0,0 +1,10 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+module SkMojo;
+
+struct FlattenedPicture { array<uint8> data; };