Add WebUSB bindings and client interface

Source/modules/webusb/USBError.h

Index: Source/modules/webusb/USBError.h
diff --git a/Source/modules/webusb/USBError.h b/Source/modules/webusb/USBError.h
new file mode 100644
index 0000000000000000000000000000000000000000..8916c2f10bc67bd5ea242d6e86d236ad60392b87
--- /dev/null
+++ b/Source/modules/webusb/USBError.h
@@ -0,0 +1,32 @@
+// 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 USBError_h
+#define USBError_h
+
+#include "platform/heap/Handle.h"
+#include "public/platform/modules/webusb/WebUSBError.h"
+#include "wtf/PassOwnPtr.h"
+
+namespace blink {
+
+class DOMException;
+class ScriptPromiseResolver;
+
+// USBError is used with CallbackPromiseAdapter to receive WebUSBError
+// responses. See CallbackPromiseAdapter class comments.
+class USBError {
+    WTF_MAKE_NONCOPYABLE(USBError);
+public:
+    // Interface required by CallbackPromiseAdapter:
+    typedef WebUSBError WebType;
+    static DOMException* take(ScriptPromiseResolver*, PassOwnPtr<WebUSBError>);
+
+private:
+    USBError() = delete;
+};
+
+} // namespace blink
+
+#endif // USBError_h