diff -r 000000000000 -r 6474c204b198 toolkit/components/thumbnails/test/browser_thumbnails_storage.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/components/thumbnails/test/browser_thumbnails_storage.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,101 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+const URL = "http://mochi.test:8888/";
+const URL_COPY = URL + "#copy";
+
+XPCOMUtils.defineLazyGetter(this, "Sanitizer", function () {
+  let tmp = {};
+  Cc["@mozilla.org/moz/jssubscript-loader;1"]
+    .getService(Ci.mozIJSSubScriptLoader)
+    .loadSubScript("chrome://browser/content/sanitize.js", tmp);
+  return tmp.Sanitizer;
+});
+
+/**
+ * These tests ensure that the thumbnail storage is working as intended.
+ * Newly captured thumbnails should be saved as files and they should as well
+ * be removed when the user sanitizes their history.
+ */
+function runTests() {
+  dontExpireThumbnailURLs([URL, URL_COPY]);
+
+  yield clearHistory();
+  yield addVisitsAndRepopulateNewTabLinks(URL, next);
+  yield createThumbnail();
+
+  // Make sure Storage.copy() updates an existing file.
+  yield PageThumbsStorage.copy(URL, URL_COPY);
+  let copy = new FileUtils.File(PageThumbsStorage.getFilePathForURL(URL_COPY));
+  let mtime = copy.lastModifiedTime -= 60;
+
+  yield PageThumbsStorage.copy(URL, URL_COPY);
+  isnot(new FileUtils.File(PageThumbsStorage.getFilePathForURL(URL_COPY)).lastModifiedTime, mtime,
+        "thumbnail file was updated");
+
+  let file = new FileUtils.File(PageThumbsStorage.getFilePathForURL(URL));
+  let fileCopy = new FileUtils.File(PageThumbsStorage.getFilePathForURL(URL_COPY));
+
+  // Clear the browser history. Retry until the files are gone because Windows
+  // locks them sometimes.
+  while (file.exists() || fileCopy.exists()) {
+    yield clearHistory();
+  }
+
+  yield addVisitsAndRepopulateNewTabLinks(URL, next);
+  yield createThumbnail();
+
+  // Clear the last 10 minutes of browsing history.
+  yield clearHistory(true);
+
+  // Retry until the file is gone because Windows locks it sometimes.
+  clearFile(file, URL);
+}
+
+function clearFile(aFile, aURL) {
+  if (aFile.exists())
+    // Re-add our URL to the history so that history observer's onDeleteURI()
+    // is called again.
+    addVisits(makeURI(aURL), function() {
+      // Try again...
+      yield clearHistory(true);
+      clearFile(aFile, aURL);
+    });
+}
+
+function clearHistory(aUseRange) {
+  let s = new Sanitizer();
+  s.prefDomain = "privacy.cpd.";
+
+  let prefs = gPrefService.getBranch(s.prefDomain);
+  prefs.setBoolPref("history", true);
+  prefs.setBoolPref("downloads", false);
+  prefs.setBoolPref("cache", false);
+  prefs.setBoolPref("cookies", false);
+  prefs.setBoolPref("formdata", false);
+  prefs.setBoolPref("offlineApps", false);
+  prefs.setBoolPref("passwords", false);
+  prefs.setBoolPref("sessions", false);
+  prefs.setBoolPref("siteSettings", false);
+
+  if (aUseRange) {
+    let usec = Date.now() * 1000;
+    s.range = [usec - 10 * 60 * 1000 * 1000, usec];
+    s.ignoreTimespan = false;
+  }
+
+  s.sanitize();
+  s.range = null;
+  s.ignoreTimespan = true;
+
+  executeSoon(next);
+}
+
+function createThumbnail() {
+  addTab(URL, function () {
+    whenFileExists(URL, function () {
+      gBrowser.removeTab(gBrowser.selectedTab);
+      next();
+    });
+  });
+}