Add Mojo IPC based input-device service.

components/input_device_service/BUILD.gn

+# 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 = [
+    "input_device_service.mojom",
+  ]
+}
+
+source_set("client") {
+  sources = [
+    "input_device_client.cc",
+    "input_device_client.h",
+  ]
+
+  deps = [
+    "//base",
+    "//services/shell/public/cpp:sources",
+    "//skia",
+    "//ui/events/devices",
+  ]
+
+  public_deps = [
+    ":interfaces",
+  ]
+}
+
+source_set("server") {
+  sources = [
+    "input_device_server.cc",
+    "input_device_server.h",
+  ]
+
+  deps = [
+    "//base",
+    "//services/shell/public/cpp:sources",
+    "//skia",
+    "//ui/events/devices",
+  ]
+
+  public_deps = [
+    ":interfaces",
+  ]
+}