Add getConfiguration method to USBDevice.

public/platform/modules/webusb/WebUSBDevice.h

Index: public/platform/modules/webusb/WebUSBDevice.h
diff --git a/public/platform/modules/webusb/WebUSBDevice.h b/public/platform/modules/webusb/WebUSBDevice.h
index dd05bf941deb310f8b110218bd5ed6733f1a6f3f..050506c90486059be8ef2439a39323316b8e6d81 100644
--- a/public/platform/modules/webusb/WebUSBDevice.h
+++ b/public/platform/modules/webusb/WebUSBDevice.h
@@ -17,6 +17,7 @@ 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&>;
@@ -72,6 +73,10 @@ public:
     // 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;