Add chrome.usb.getConfiguration and expose extra descriptors.

extensions/common/api/usb.idl

 // Copyright 2014 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.
 
 // Use the <code>chrome.usb</code> API to interact with connected USB
 // devices. This API provides access to USB operations from within the context
 // of an app. Using this API, apps can function as drivers for hardware devices.
 //
 // Errors generated by this API are reported by setting
 // $(ref:runtime.lastError) and executing the function's regular callback. The
@@ skipping 42 matching lines @@
     // Transfer direction.
     Direction direction;
     // Maximum packet size.
     long maximumPacketSize;
     // Transfer synchronization mode (isochronous only).
     SynchronizationType? synchronization;
     // Endpoint usage hint.
     UsageType? usage;
     // Polling interval (interrupt and isochronous only).
     long? pollingInterval;
+    // Extra descriptor data associated with this endpoint.
+    ArrayBuffer extra_data;
   };
 
   [noinline_doc] dictionary InterfaceDescriptor {
     // The interface number.
     long interfaceNumber;
     // The interface alternate setting number (defaults to <code>0</code).
     long alternateSetting;
     // The USB interface class.
     long interfaceClass;
     // The USB interface sub-class.
     long interfaceSubclass;
     // The USB interface protocol.
     long interfaceProtocol;
     // Description of the interface.
     DOMString? description;
     // Available endpoints.
     EndpointDescriptor[] endpoints;
+    // Extra descriptor data associated with this interface.
+    ArrayBuffer extra_data;
+  };
+
+  [noinline_doc] dictionary ConfigDescriptor {
+    // The configuration number.
+    long configurationValue;
+    // Description of the configuration.
+    DOMString? description;
+    // The device is self-powered.
+    boolean selfPowered;
+    // The device supports remote wakeup.
+    boolean remoteWakeup;
+    // The maximum power needed by this device in milliamps (mA).
+    long maxPower;
+    // Available interfaces.
+    InterfaceDescriptor[] interfaces;
+    // Extra descriptor data associated with this configuration.
+    ArrayBuffer extra_data;
   };
 
   dictionary ControlTransferInfo {
     // The transfer direction (<code>"in"</code> or <code>"out"</code>).
     Direction direction;
 
     // The transfer target. The target given by <code>index</code> must be
     // claimed if <code>"interface"</code> or <code>"endpoint"</code>.
     Recipient recipient;
 
@@ skipping 84 matching lines @@
     // The interface ID to request access to.
     // Only available on ChromeOS. It has no effect on other platforms.
     long? interfaceId;
   };
 
   callback VoidCallback = void ();
   callback GetDevicesCallback = void (Device[] devices);
   callback RequestAccessCallback = void (boolean success);
   callback OpenDeviceCallback = void (ConnectionHandle handle);
   callback FindDevicesCallback = void (ConnectionHandle[] handles);
+  callback GetConfigurationCallback = void (ConfigDescriptor config);
   callback ListInterfacesCallback = void (InterfaceDescriptor[] descriptors);
   callback CloseDeviceCallback = void ();
   callback TransferCallback = void (TransferResultInfo info);
   callback ResetDeviceCallback = void(boolean success);
 
   interface Functions {
     // Enumerates connected USB devices.
     // |options|: The properties to search for on target devices.
     static void getDevices(EnumerateDevicesOptions options,
                            GetDevicesCallback callback);
@@ skipping 31 matching lines @@
     // |options|: The properties to search for on target devices.
     static void findDevices(EnumerateDevicesAndRequestAccessOptions options,
                             FindDevicesCallback callback);
 
     // Closes a connection handle. Invoking operations on a handle after it
     // has been closed is a safe operation but causes no action to be taken.
     // |handle|: The $(ref:ConnectionHandle) to close.
     static void closeDevice(ConnectionHandle handle,
                             optional CloseDeviceCallback callback);
 
+    // Gets the configuration descriptor for the currently selected
+    // configuration.
+    // |handle|: An open connection to the device.
+    static void getConfiguration(ConnectionHandle handle,
+                                 GetConfigurationCallback callback);
+
     // Lists all interfaces on a USB device.
     // |handle|: An open connection to the device.
     static void listInterfaces(ConnectionHandle handle,
                                ListInterfacesCallback callback);
 
     // Claims an interface on a USB device.
     // Before data can be transfered to an interface or associated endpoints the
     // interface must be claimed. Only one connection handle can claim an
     // interface at any given time. If the interface is already claimed, this
     // call will fail.
@@ skipping 57 matching lines @@
     // If the reset fails, the given connection handle will be closed and the 
     // USB device will appear to be disconnected then reconnected. 
     // In this case $(ref:getDevices) or $(ref:findDevices) must be called again
     // to acquire the device.
     //
     // |handle|: A connection handle to reset.
     static void resetDevice(ConnectionHandle handle,
                             ResetDeviceCallback callback);
   };
 };