Revert of arc-bridge: Move most methods to Mojo interfaces

components/arc/common/input.mojom

-// Copyright 2015 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 arc;
-
-interface InputInstance {
-  // Registers a virtual input device on the container side.
-  // |name| is the device name, like "Chrome OS Keyboard".
-  // |device_type| is the device type, like "keyboard".
-  // The virtual device will be reading 'struct input_event's from |fd|.  The
-  // ownership of |fd| will be transferred to the receiver, so the sender must
-  // not close it.
-  RegisterInputDevice(string name,
-                      string device_type,
-                      handle fd);
-};