Add WebUSB bindings and client interface

public/platform/modules/webusb/WebUSBTransferInfo.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 WebUSBTransferInfo_h
+#define WebUSBTransferInfo_h
+
+#include "public/platform/WebVector.h"
+
+namespace blink {
+
+// Information about a completed USB transfer.
+struct WebUSBTransferInfo {
+    enum Status {
+        StatusOk,
+        StatusStall,
+        StatusBabble,
+    };
+
+    WebUSBTransferInfo()
+        : status(StatusOk)
+        , bytesWritten(0)
+    {
+    }
+
+    Status status;
+
+    // Data received, if this is an inbound transfer.
+    WebVector<uint8_t> data;
+
+    // Number of bytes written if this is an outbound transfer.
+    uint32_t bytesWritten;
+};
+
+} // namespace blink
+
+#endif // WebUSBTransferInfo_h