Add webusb notification UI code

chrome/browser/chrome_webusb_browser_client.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 CHROME_BROWSER_CHROME_WEBUSB_BROWSER_CLIENT_H_
+#define CHROME_BROWSER_CHROME_WEBUSB_BROWSER_CLIENT_H_
+
+#include "components/webusb/webusb_browser_client.h"
+
+class GURL;
+
+// Implementation of webusb::WebUsbBrowserClient.
+// singletons appropriate for use within the Chrome application.
+class ChromeWebUsbBrowserClient : public webusb::WebUsbBrowserClient {
+ public:
+  ChromeWebUsbBrowserClient();
+  ~ChromeWebUsbBrowserClient() override;
+
+  // webusb::WebUsbBrowserClient implementation
+  void OpenURL(const GURL& url) override;
+
+  // webusb::WebUsbBrowserClient implementation
+  bool WebUsbNotificationEnabled() override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ChromeWebUsbBrowserClient);
+};
+
+#endif  // CHROME_BROWSER_CHROME_WEBUSB_BROWSER_CLIENT_H_