Convert DeviceManagerDelegate to PermissionProvider mojo interface.

device/devices_app/usb/public/interfaces/device_manager.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 device.usb;
 
 import "device.mojom";
 
 enum OpenDeviceError {
   // Opening the device succeeded.
@@ skipping 17 matching lines @@
   uint8 class_code;
 
   bool has_subclass_code;
   uint8 subclass_code;
 
   bool has_protocol_code;
   uint8 protocol_code;
 };
 
 struct EnumerationOptions {
-  array<DeviceFilter> filters;
+  array<DeviceFilter>? filters;
 };
 
 struct DeviceChangeNotification {
   array<DeviceInfo> devices_added;
   array<string> devices_removed;
 };
 
 interface DeviceManager {
   // Retrieves information about all devices available to the DeviceManager
   // implementation.
-  GetDevices(EnumerationOptions options) => (array<DeviceInfo> results);
+  GetDevices(EnumerationOptions? options) => (array<DeviceInfo> results);
 
   // Retrieves information about changes to the set of devices available to the
-  // DeviceManager since the last call to this method. The first call will
-  // return the set of all devices available. Device added and removed between
-  // calls will not be included.
+  // DeviceManager since the last call to this method. A device that is added
+  // and removed between calls will not be included.
   GetDeviceChanges() => (DeviceChangeNotification changes);
 
   // Attempts to open a device given its GUID.
   OpenDevice(string guid, Device& device_request) => (OpenDeviceError error);
 };