Track USB device configuration state in Blink.

device/usb/public/interfaces/device.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;
 
 enum OpenDeviceError {
   // Opening the device succeeded.
   OK,
 
@@ skipping 81 matching lines @@
   uint8 subclass_code;
   uint8 protocol_code;
   uint16 vendor_id;
   uint16 product_id;
   uint8 device_version_major;
   uint8 device_version_minor;
   uint8 device_version_subminor;
   string? manufacturer_name;
   string? product_name;
   string? serial_number;
+  uint8 active_configuration;
   array<ConfigurationInfo> configurations;
   WebUsbDescriptorSet? webusb_allowed_origins;
 };
 
 struct ControlTransferParams {
   ControlTransferType type;
   ControlTransferRecipient recipient;
   uint8 request;
   uint16 value;
   uint16 index;
@@ skipping 34 matching lines @@
   uint32 length;
   uint32 transferred_length;
   TransferStatus status;
 };
 
 interface Device {
   // Retrieve a DeviceInfo struct containing metadata about the device,
   // including the set of all available device configurations.
   GetDeviceInfo() => (DeviceInfo? info);
 
-  // Retrieves the |configuration_value| of the device's currently active
-  // configuration. Will return 0 if the device is unconfigured.
-  GetConfiguration() => (uint8 value);
-
   // Opens the device. Methods below require the device be opened first.
   Open() => (OpenDeviceError error);
 
   // Closes the device.
   Close() => ();
 
   // Initiates a device control transfer to set the device's configuration to
   // one with the configuration value |value|.
   SetConfiguration(uint8 value) => (bool success);
 
@@ skipping 109 matching lines @@
   // indicates no timeout: the request will remain pending indefinitely until
   // completed or otherwise terminated.
 
   // |packets| contains the status of each packet sent to the device, in order.
   IsochronousTransferOut(uint8 endpoint_number,
                          array<uint8> data,
                          array<uint32> packet_lengths,
                          uint32 timeout)
       => (array<IsochronousPacket> packets);
 };