Remove unused whitelist code.

Technically it was "whitelsited_url", but definitely still not inclusive.

Bug: 842296
Change-Id: I559972553b49e09423f40f59492b9c43f0faa1fa
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2538269
Commit-Queue: Darwin Huang <huangdarwin@chromium.org>
Commit-Queue: Aga Wronska <agawronska@chromium.org>
Auto-Submit: Darwin Huang <huangdarwin@chromium.org>
Reviewed-by: Aga Wronska <agawronska@chromium.org>
Cr-Commit-Position: refs/heads/master@{#827510}

chrome/browser/chromeos/child_accounts/time_limits/web_time_limit_enforcer_browsertest.cc

@@ -438,8 +438,6 @@ IN_PROC_BROWSER_TEST_F(WebTimeLimitEnforcerThrottleTest, WebContentTitleSet) {
 }
 
 IN_PROC_BROWSER_TEST_F(WebTimeLimitEnforcerThrottleTest, EnsureQueryIsCleared) {
-  GURL whitelsited_url = embedded_test_server()->GetURL(
-      kExampleHost, "/supervised_user/simple.html");
   AllowlistUrlRegx(kExampleHost);
   BlockWeb();