Remove knowledge of USB devices from permission prompt implementations.

extensions/browser/api/usb/usb_apitest.cc

Index: extensions/browser/api/usb/usb_apitest.cc
diff --git a/extensions/browser/api/usb/usb_apitest.cc b/extensions/browser/api/usb/usb_apitest.cc
index d2be33cb8406adc52499706951dcf32a198f1e9b..affc107661860f74a50edb64385d9bb5ae4edbb8 100644
--- a/extensions/browser/api/usb/usb_apitest.cc
+++ b/extensions/browser/api/usb/usb_apitest.cc
@@ -54,15 +54,13 @@ class TestDevicePermissionsPrompt
   void ShowDialog() override { prompt()->SetObserver(this); }
 
   void OnDevicesChanged() override {
-    std::vector<scoped_refptr<UsbDevice>> devices;
     for (size_t i = 0; i < prompt()->GetDeviceCount(); ++i) {
       prompt()->GrantDevicePermission(i);
-      devices.push_back(prompt()->GetDevice(i));
       if (!prompt()->multiple()) {
         break;
       }
     }
-    delegate()->OnUsbDevicesChosen(devices);
+    prompt()->Dismissed();
   }
 };