chromeos: adds TouchDeviceServer and wires up in mushrome

services/ui/public/interfaces/input_devices/touch_device_server.mojom

+// Copyright 2017 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;
+
+import "ui/display/manager/chromeos/mojo/touch_device_transform.mojom";
+
+interface TouchDeviceServer {
+  // Reset the touch configuration. |scales| maps from touch_id to the scale.
+  ConfigureTouchDevices(map<int32, double> scales,

[Elliot Glaysher, 2017/05/22 17:54:44]

slightly off topic: is it the correct thing for mojo maps to resolve to
std::unordered_map<>? I remember it coming up on the ml that unordered_maps were
larger for small number of items.

[sky, 2017/05/22 18:04:04]

715340 is against whether mojo bindings should still use unordered_map.

+                        array<display.mojom.TouchDeviceTransform> transforms);
+};