Add getConfiguration method to USBDevice.

Source/modules/webusb/USBConfiguration.cpp

 // 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.
 
 #include "config.h"
 #include "modules/webusb/USBConfiguration.h"
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "modules/webusb/USBDevice.h"
 #include "modules/webusb/USBInterface.h"
 
 namespace blink {
 
 USBConfiguration* USBConfiguration::create(const USBDevice* device, size_t configurationIndex)
 {
     return new USBConfiguration(device, configurationIndex);
 }
 
 USBConfiguration* USBConfiguration::create(const USBDevice* device, size_t configurationValue, ExceptionState& exceptionState)
 {
     for (size_t i = 0; i < device->info().configurations.size(); ++i) {
         if (device->info().configurations[i].configurationValue == configurationValue)
             return new USBConfiguration(device, i);
     }
     exceptionState.throwRangeError("Invalid configuration value.");
     return nullptr;
 }
 
+USBConfiguration* USBConfiguration::createFromValue(const USBDevice* device, uint8_t configurationValue)
+{
+    for (size_t i = 0; i < device->info().configurations.size(); ++i) {
+        if (device->info().configurations[i].configurationValue == configurationValue)
+            return new USBConfiguration(device, i);
+    }
+    return nullptr;
+}
+
 USBConfiguration::USBConfiguration(const USBDevice* device, size_t configurationIndex)
     : m_device(device)
     , m_configurationIndex(configurationIndex)
 {
     ASSERT(m_device);
     ASSERT(m_configurationIndex < m_device->info().configurations.size());
 }
 
 const WebUSBDeviceInfo::Configuration& USBConfiguration::info() const
 {
@@ skipping 17 matching lines @@
         interfaces.append(USBInterface::create(this, i));
     return interfaces;
 }
 
 DEFINE_TRACE(USBConfiguration)
 {
     visitor->trace(m_device);
 }
 
 } // namespace blink