Bug 720985 - Make some tests stop polluting the global scope

browser/base/content/test/newtab/head.js

@@ -5,7 +5,9 @@ const PREF_NEWTAB_ENABLED = "browser.newtabpage.enabled";
 
 Services.prefs.setBoolPref(PREF_NEWTAB_ENABLED, true);
 
-Cu.import("resource:///modules/NewTabUtils.jsm");
+let tmp = {};
+Cu.import("resource:///modules/NewTabUtils.jsm", tmp);
+let NewTabUtils = tmp.NewTabUtils;
 
 registerCleanupFunction(function () {
   reset();

browser/components/thumbnails/test/head.js

@@ -1,7 +1,10 @@
 /* Any copyright is dedicated to the Public Domain.
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
-Cu.import("resource:///modules/PageThumbs.jsm");
+let tmp = {};
+Cu.import("resource:///modules/PageThumbs.jsm", tmp);
+let PageThumbs = tmp.PageThumbs;
+let PageThumbsCache = tmp.PageThumbsCache;
 
 registerCleanupFunction(function () {
   while (gBrowser.tabs.length > 1)

browser/devtools/tilt/test/browser_tilt_utils05.js

@@ -2,7 +2,9 @@
    http://creativecommons.org/publicdomain/zero/1.0/ */
 "use strict";
 
-Cu.import("resource:///modules/devtools/LayoutHelpers.jsm");
+let tmp = {};
+Cu.import("resource:///modules/devtools/LayoutHelpers.jsm", tmp);
+let LayoutHelpers = tmp.LayoutHelpers;
 
 function init(callback) {
   let iframe = gBrowser.ownerDocument.createElement("iframe");

browser/devtools/webconsole/test/browser_gcli_commands.js

@@ -5,7 +5,9 @@
 // - https://github.com/mozilla/gcli/blob/master/docs/index.md
 // - https://wiki.mozilla.org/DevTools/Features/GCLI
 
-Components.utils.import("resource:///modules/gcli.jsm");
+let tmp = {};
+Components.utils.import("resource:///modules/gcli.jsm", tmp);
+let gcli = tmp.gcli;
 
 let hud;
 let gcliterm;