Add beginnings of an inspector backend for Sky

sky/framework/inspector/server/inspector.mojom

+// Copyright 2014 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 sky {
+
+[Client=InspectorBackend]
+interface InspectorFrontend {
+  Listen(int32 port);
+  SendMessage(string message);
+};
+
+[Client=InspectorFrontend]
+interface InspectorBackend {
+  OnConnect();
+  OnDisconnect();
+  OnMessage(string message);
+};
+
+}