[WebNFC] Add permission prompt for NDEFReader.scan

This CL makes sure NDEFReader.scan shows a permission request if user
didn't previously allow Web NFC.

Screenshots: https://photos.app.goo.gl/k7wz55v9ELVTS19i8

Bug:520391
Change-Id: I10125c8db9a4b1cdd3476939bdf650583c7f19b3

lint.whitelist

@@ -678,6 +678,8 @@ LAYOUTTESTS APIS: import-maps/resources/jest-test-helper.js
 LAYOUTTESTS APIS: resources/chromium/generic_sensor_mocks.js
 LAYOUTTESTS APIS: resources/chromium/nfc-mock.js
 LAYOUTTESTS APIS: resources/chromium/webxr-test.js
+LAYOUTTESTS APIS: web-nfc/NDEFReader-document-hidden-manual.https.html
+LAYOUTTESTS APIS: web-nfc/NDEFReader_scan.https.html
 LAYOUTTESTS APIS: web-nfc/NDEFWriter_push.https.html
 
 # Signed Exchange files have hard-coded URLs in the certUrl field

web-nfc/NDEFReader-document-hidden-manual.https.html

@@ -14,6 +14,11 @@
     if (document.hidden) reject();
     resolve();
   });
+  if (window.testRunner) {
+    // Grant nfc permissions for Chromium testrunner.
+    window.testRunner.setPermission('nfc', 'granted',
+                                    location.origin, location.origin);
+  }
   await reader.scan();
   await promise;
 }, "Test NDEFReader.onreading is not fired when document is hidden");

web-nfc/NDEFReader_scan.https.html

@@ -49,6 +49,16 @@
 }, "Test that NDEFReader.scan rejects if NDEFScanOptions.id has wrong \
 protocol.");
 
+promise_test(async t => {
+  if (window.testRunner) {
+    // Deny nfc permissions for Chromium testrunner.
+    window.testRunner.setPermission('nfc', 'denied',
+                                    location.origin, location.origin);
+  }
+  const reader = new NDEFReader();
+  await promise_rejects(t, 'NotAllowedError', reader.scan());
+}, "NDEFReader.scan should fail if user permission is not granted.");
+
 nfc_test(async (t, mockNFC) => {
   mockNFC.setHWStatus(NFCHWStatus.DISABLED);
   const reader = new NDEFReader();