mus/gpu: Introduce the GpuServiceHost mojom interface.

services/ui/gpu/interfaces/context_lost_reason.mojom

Index: services/ui/gpu/interfaces/context_lost_reason.mojom
diff --git a/services/ui/gpu/interfaces/context_lost_reason.mojom b/services/ui/gpu/interfaces/context_lost_reason.mojom
new file mode 100644
index 0000000000000000000000000000000000000000..d9b771244e6dbcfc9f7c4d4c5c07cba74510e43f
--- /dev/null
+++ b/services/ui/gpu/interfaces/context_lost_reason.mojom
@@ -0,0 +1,15 @@
+// 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.
+
+module ui.mojom;
+
+enum ContextLostReason {
+  GUILTY,
+  INNOCENT,
+  UNKNOWN,
+  OUT_OF_MEMORY,
+  MAKE_CURRENT_FAILED,
+  GPU_CHANNEL_LOST,
+  INVALID_GPU_MESSAGE,
+};