Add getConfiguration method to USBDevice.

public/platform/modules/webusb/WebUSBDevice.h

 // 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.
 
 #ifndef WebUSBDevice_h
 #define WebUSBDevice_h
 
 #include "public/platform/WebCallbacks.h"
 #include "public/platform/WebPassOwnPtr.h"
 #include "public/platform/WebVector.h"
 
 namespace blink {
 
 struct WebUSBDeviceInfo;
 struct WebUSBError;
 struct WebUSBTransferInfo;
 
 using WebUSBDeviceOpenCallbacks = WebCallbacks<void, const WebUSBError&>;
 using WebUSBDeviceCloseCallbacks = WebCallbacks<void, const WebUSBError&>;
+using WebUSBDeviceGetConfigurationCallbacks = WebCallbacks<uint8_t, const WebUSBError&>;
 using WebUSBDeviceSetConfigurationCallbacks = WebCallbacks<void, const WebUSBError&>;
 using WebUSBDeviceClaimInterfaceCallbacks = WebCallbacks<void, const WebUSBError&>;
 using WebUSBDeviceReleaseInterfaceCallbacks = WebCallbacks<void, const WebUSBError&>;
 using WebUSBDeviceResetCallbacks = WebCallbacks<void, const WebUSBError&>;
 using WebUSBDeviceSetInterfaceAlternateSettingCallbacks = WebCallbacks<void, const WebUSBError&>;
 using WebUSBDeviceClearHaltCallbacks = WebCallbacks<void, const WebUSBError&>;
 using WebUSBDeviceTransferCallbacks = WebCallbacks<WebPassOwnPtr<WebUSBTransferInfo>, const WebUSBError&>;
 
 // TODO(rockot): Eliminate these aliases once they're no longer used outside of
 // Blink code.
@@ skipping 35 matching lines @@
     virtual const WebUSBDeviceInfo& info() const = 0;
 
     // Opens the device.
     // Ownership of the WebUSBDeviceOpenCallbacks is transferred to the client.
     virtual void open(WebUSBDeviceOpenCallbacks*) = 0;
 
     // Closes the device.
     // Ownership of the WebUSBDeviceCloseCallbacks is transferred to the client.
     virtual void close(WebUSBDeviceCloseCallbacks*) = 0;
 
+    // Gets the active configuration of the device.
+    // Ownership of the WebUSBDeviceGetConfigurationCallbacks is transferred to the client.
+    virtual void getConfiguration(WebUSBDeviceGetConfigurationCallbacks*) { }
+
     // Sets the active configuration for the device.
     // Ownership of the WebUSBDeviceSetConfigurationCallbacks is transferred to the client.
     virtual void setConfiguration(uint8_t configurationValue, WebUSBDeviceSetConfigurationCallbacks*) = 0;
 
     // Claims an interface in the active configuration.
     // Ownership of the WebUSBDeviceClaimInterfaceCallbacks is transferred to the client.
     virtual void claimInterface(uint8_t interfaceNumber, WebUSBDeviceClaimInterfaceCallbacks*) = 0;
 
     // Releases a claimed interface.
     // Ownership of the WebUSBDeviceReleaseInterfaceCallbacks is transferred to the client.
@@ skipping 16 matching lines @@
     virtual void transfer(TransferDirection, uint8_t endpointNumber, uint8_t* data, size_t dataSize, unsigned timeout, WebUSBDeviceBulkTransferCallbacks*) = 0;
 
     // Resets the device.
     // Ownership of the WebUSBDeviceResetCallbacks is transferred to the client.
     virtual void reset(WebUSBDeviceResetCallbacks*) = 0;
 };
 
 } // namespace blink
 
 #endif // WebUSBDevice_h