Remove left-over PageCache stuff

LayoutTests/http/tests/navigation/resources/https-in-page-cache-2.php

-<?php
-header("cache-control: no-cache");
-?>
-<script>
-
-function nextTest() {
-        if (window.sessionStorage.https_in_page_cache_started)
-                delete window.sessionStorage.https_in_page_cache_started;
-        location = "https://127.0.0.1:8443/navigation/resources/https-in-page-cache-3.html";
-}
-
-window.onpageshow = function(evt) {
-        if (evt.persisted) {
-                alert("The page was restored from the page cache. It should NOT have been. Running part 3 of the test.");
-                nextTest();
-        }
-}
-
-window.onload = function() {
-        if (window.sessionStorage.https_in_page_cache_started) {
-                alert("The page was reloaded on back, not from the page cache. Good job. Running part 3 of the test.");
-                nextTest();
-                return;
-        }
-
-        alert("This page is https and has the no-cache cache-control directive. It should NOT go in to the page cache.");
-        window.sessionStorage.https_in_page_cache_started = true;
-        setTimeout('window.location = "go-back.html"', 0);
-
-}
-
-</script>