[WebNFC] Require mediaType only for json and opaque NDEFRecords

This CL makes sure a mediaType is required only if recordType is "json"
or "opaque" in a NDEFRecord as described at
https://w3c.github.io/web-nfc/#data-mapping

Bug: 1013167
Change-Id: I22a6508b66e5e5e7f69ca295fd5281b02dcb2b6d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1852215
Commit-Queue: François Beaufort <beaufort.francois@gmail.com>
Reviewed-by: Rijubrata Bhaumik <rijubrata.bhaumik@intel.com>
Cr-Commit-Position: refs/heads/master@{#705089}

services/device/nfc/android/java/src/org/chromium/device/nfc/NdefMessageValidator.java

@@ -35,6 +35,12 @@ public final class NdefMessageValidator {
     private static boolean isValid(NdefRecord record) {
         if (record == null) return false;
         if (record.recordType.equals(NdefMessageUtils.RECORD_TYPE_EMPTY)) return true;
-        return record.data != null && record.mediaType != null && !record.mediaType.isEmpty();
+        if (record.data == null) return false;
+        if ((record.recordType.equals(NdefMessageUtils.RECORD_TYPE_JSON)
+                    || record.recordType.equals(NdefMessageUtils.RECORD_TYPE_OPAQUE))
+                && (record.mediaType == null || record.mediaType.isEmpty())) {
+            return false;
+        }
+        return true;
     }
 }