Use interface associations to check function permissions.

device/usb/mojo/permission_provider.h

 // 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.
 
 #ifndef DEVICE_USB_MOJO_PERMISSION_PROVIDER_H_
 #define DEVICE_USB_MOJO_PERMISSION_PROVIDER_H_
 
 #include <stdint.h>
 
 namespace device {
 namespace usb {
 
 class DeviceInfo;
 
 // An implementation of this interface must be provided to a DeviceManager in
 // order to implement device permission checks.
 class PermissionProvider {
  public:
   PermissionProvider();
   virtual ~PermissionProvider();
 
   virtual bool HasDevicePermission(const DeviceInfo& device_info) const = 0;
   virtual bool HasConfigurationPermission(
       uint8_t requested_configuration,
       const DeviceInfo& device_info) const = 0;
-  virtual bool HasInterfacePermission(uint8_t requested_interface,
-                                      uint8_t configuration_value,
-                                      const DeviceInfo& device_info) const = 0;
+  virtual bool HasFunctionPermission(uint8_t requested_function,
+                                     uint8_t configuration_value,
+                                     const DeviceInfo& device_info) const = 0;
 };
 
 }  // namespace usb
 }  // namespace device
 
 #endif  // DEVICE_USB_MOJO_PERMISSION_PROVIDER_H_