Add webusb notification UI code

components/webusb.gypi

+# 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.
+
+{
+  'targets': [
+    {
+      'target_name': 'webusb',
+      'type': 'static_library',
+      'dependencies': [
+        '../base/base.gyp:base',
+        '../device/core/core.gyp:device_core',
+        '../device/usb/usb.gyp:device_usb',
+        '../ui/base/ui_base.gyp:ui_base',
+        '../ui/gfx/gfx.gyp:gfx',
+        '../ui/message_center/message_center.gyp:message_center',
+        '../url/url.gyp:url_lib',
+        'components_strings.gyp:components_strings',
+      ],
+      'include_dirs': [
+        '..',
+      ],
+      'sources': [
+        'webusb/webusb_browser_client.cc',
+        'webusb/webusb_browser_client.h',
+        'webusb/webusb_detector.cc',
+        'webusb/webusb_detector.h',
+      ],
+    },
+  ],
+}