Add WebUSB bindings and client interface [part 1]

public/platform/modules/webusb/WebUSBDeviceEnumerationOptions.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 WebUSBDeviceEnumerationOptions_h
+#define WebUSBDeviceEnumerationOptions_h
+
+#include "public/platform/WebVector.h"
+#include "public/platform/modules/webusb/WebUSBDeviceFilter.h"
+
+namespace blink {
+
+// Options which constrain the set of devices returned in device enumeration.
+struct WebUSBDeviceEnumerationOptions {
+    WebVector<WebUSBDeviceFilter> filters;
+};
+
+} // namespace blink
+
+#endif // WebUSBDeviceEnumerationOptions_h