[DeviceService] Move screen_orientation.mojom from //content to //device.

device/screen_orientation/public/interfaces/BUILD.gn

Index: device/screen_orientation/public/interfaces/BUILD.gn
diff --git a/device/screen_orientation/public/interfaces/BUILD.gn b/device/screen_orientation/public/interfaces/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..0f2e547e3fde6986c5ba43b5b0d4912bd70b2f1b
--- /dev/null
+++ b/device/screen_orientation/public/interfaces/BUILD.gn
@@ -0,0 +1,12 @@
+# Copyright 2016 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.
+
+import("//mojo/public/tools/bindings/mojom.gni")
+
+mojom("interfaces") {
+  sources = [
+    "screen_orientation.mojom",
+    "screen_orientation_lock_types.mojom",
+  ]
+}