From https://codereview.chromium.org/2886433002/diff/250001/components/content_settings/core/browser/host_content_settings_map.cc#newcode406 :

We need something to ensure effectively the same as the following would do within HostContentSettingsMap::SetWebsiteSettingCustomScope, but in a neater way. (Ideally enforced at compile time - but that may be a bigger project):

#if defined(OS_ANDROID) && DCHECK_IS_ON()
  // The notification permission on Android only allows valid origins with a
  // restricted set of settings, or the global wildcard origin.
  if (content_type == CONTENT_SETTINGS_TYPE_NOTIFICATIONS &&
      !primary_pattern.MatchesAllHosts()) {
    // The |primary_pattern| must be a valid GURL as it may be presented to the
    // user: Android Notification Channels may be used on Android O onward.
    DCHECK(GURL(primary_pattern.ToString()).is_valid());

    ContentSetting setting =
        content_settings::ValueToContentSetting(value.get());

    // Disallow notification content setting updates for specific origins that
    // are not ALLOW/BLOCK/DEFAULT on Android.
    DCHECK(setting == CONTENT_SETTING_ALLOW ||
           setting == CONTENT_SETTING_BLOCK ||
           setting == CONTENT_SETTING_DEFAULT);
  }
#endif