Integrate WebUSB with Feature Policy

chrome/browser/usb/usb_chooser_controller.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_USB_USB_CHOOSER_CONTROLLER_H_
 #define CHROME_BROWSER_USB_USB_CHOOSER_CONTROLLER_H_
 
 #include <unordered_map>
 #include <utility>
 #include <vector>
@@ skipping 48 matching lines @@
 
  private:
   void GotUsbDeviceList(
       const std::vector<scoped_refptr<device::UsbDevice>>& devices);
   bool DisplayDevice(scoped_refptr<device::UsbDevice> device) const;
 
   std::vector<device::UsbDeviceFilter> filters_;
   device::mojom::UsbChooserService::GetPermissionCallback callback_;
   GURL requesting_origin_;
   GURL embedding_origin_;
-  bool is_embedded_frame_;
 
   base::WeakPtr<UsbChooserContext> chooser_context_;
   ScopedObserver<device::UsbService, device::UsbService::Observer>
       usb_service_observer_;
 
   // Each pair is a (device, device name).
   std::vector<std::pair<scoped_refptr<device::UsbDevice>, base::string16>>
       devices_;
   // Maps from device name to number of devices.
   std::unordered_map<base::string16, int> device_name_map_;
   base::WeakPtrFactory<UsbChooserController> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(UsbChooserController);
 };
 
 #endif  // CHROME_BROWSER_USB_USB_CHOOSER_CONTROLLER_H_