Roll 50: Copied IDLs, PYTHON scripts from WebKit removed deleted files in WebCore

modules/webusb/USBAlternateInterface.idl

+// 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.
+
+// http://wicg.github.io/webusb/#interfaces
+
+[
+    Constructor(USBInterface deviceInterface, octet alternateSetting),
+    RaisesException=Constructor,
+    GarbageCollected,
+    RuntimeEnabled=WebUSB,
+] interface USBAlternateInterface {
+    readonly attribute octet alternateSetting;
+    readonly attribute octet interfaceClass;
+    readonly attribute octet interfaceSubclass;
+    readonly attribute octet interfaceProtocol;
+    readonly attribute DOMString? interfaceName;
+    readonly attribute sequence<USBEndpoint> endpoints;
+};