Add --disable-webusb-security flag for testing existing devices.

chrome/browser/usb/usb_chooser_bubble_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_BUBBLE_CONTROLLER_H_
 #define CHROME_BROWSER_USB_USB_CHOOSER_BUBBLE_CONTROLLER_H_
 
 #include <utility>
 
 #include "base/macros.h"
@@ skipping 36 matching lines @@
 
   // device::UsbService::Observer:
   void OnDeviceAdded(scoped_refptr<device::UsbDevice> device) override;
   void OnDeviceRemoved(scoped_refptr<device::UsbDevice> device) override;
 
   void set_bubble_reference(BubbleReference bubble_reference);
 
  private:
   void GotUsbDeviceList(
       const std::vector<scoped_refptr<device::UsbDevice>>& devices);
+  bool DisplayDevice(scoped_refptr<device::UsbDevice> device) const;
 
   content::RenderFrameHost* const render_frame_host_;
   device::usb::ChooserService::GetPermissionCallback callback_;
   ScopedObserver<device::UsbService, device::UsbService::Observer>
       usb_service_observer_;
   std::vector<device::UsbDeviceFilter> filters_;
   // Each pair is a (device, device name).
   std::vector<std::pair<scoped_refptr<device::UsbDevice>, base::string16>>
       devices_;
   BubbleReference bubble_reference_;
   base::WeakPtrFactory<UsbChooserBubbleController> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(UsbChooserBubbleController);
 };
 
 #endif  // CHROME_BROWSER_USB_USB_CHOOSER_BUBBLE_CONTROLLER_H_