diff -r 000000000000 -r 6474c204b198 toolkit/components/thumbnails/test/browser_thumbnails_privacy.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/components/thumbnails/test/browser_thumbnails_privacy.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,74 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+const PREF_DISK_CACHE_SSL = "browser.cache.disk_cache_ssl";
+const URL = "://example.com/browser/toolkit/components/thumbnails/" +
+            "test/privacy_cache_control.sjs";
+
+function runTests() {
+  registerCleanupFunction(function () {
+    Services.prefs.clearUserPref(PREF_DISK_CACHE_SSL);
+  });
+
+  let positive = [
+    // A normal HTTP page without any Cache-Control header.
+    {scheme: "http", cacheControl: null, diskCacheSSL: false},
+
+    // A normal HTTP page with 'Cache-Control: private'.
+    {scheme: "http", cacheControl: "private", diskCacheSSL: false},
+
+    // Capture HTTPS pages if browser.cache.disk_cache_ssl == true.
+    {scheme: "https", cacheControl: null, diskCacheSSL: true},
+    {scheme: "https", cacheControl: "public", diskCacheSSL: true},
+    {scheme: "https", cacheControl: "private", diskCacheSSL: true}
+  ];
+
+  let negative = [
+    // Never capture pages with 'Cache-Control: no-store'.
+    {scheme: "http", cacheControl: "no-store", diskCacheSSL: false},
+    {scheme: "http", cacheControl: "no-store", diskCacheSSL: true},
+    {scheme: "https", cacheControl: "no-store", diskCacheSSL: false},
+    {scheme: "https", cacheControl: "no-store", diskCacheSSL: true},
+
+    // Don't capture HTTPS pages by default.
+    {scheme: "https", cacheControl: null, diskCacheSSL: false},
+    {scheme: "https", cacheControl: "public", diskCacheSSL: false},
+    {scheme: "https", cacheControl: "private", diskCacheSSL: false}
+  ];
+
+  let urls = positive.map((combi) => {
+    let url = combi.scheme + URL;
+    if (combi.cacheControl)
+      url += "?" + combi.cacheControl;
+    return url;
+  });
+  yield addVisitsAndRepopulateNewTabLinks(urls, next);
+
+  yield checkCombinations(positive, true);
+  yield checkCombinations(negative, false);
+}
+
+function checkCombinations(aCombinations, aResult) {
+  let combi = aCombinations.shift();
+  if (!combi) {
+    next();
+    return;
+  }
+
+  let url = combi.scheme + URL;
+  if (combi.cacheControl)
+    url += "?" + combi.cacheControl;
+  Services.prefs.setBoolPref(PREF_DISK_CACHE_SSL, combi.diskCacheSSL);
+
+  let tab = gBrowser.selectedTab = gBrowser.addTab(url);
+  let browser = gBrowser.selectedBrowser;
+
+  whenLoaded(browser, function () {
+    let msg = JSON.stringify(combi) + " == " + aResult;
+    is(gBrowserThumbnails._shouldCapture(browser), aResult, msg);
+    gBrowser.removeTab(tab);
+
+    // Continue with the next combination.
+    checkCombinations(aCombinations, aResult);
+  });
+}