Bug 1431533: Part 5a - Auto-rewrite code to use ChromeUtils import methods. r=florian

This was done using the following script:
37e3803c7a/processors/chromeutils-import.jsm

MozReview-Commit-ID: 1Nc3XDu0wGl

browser/base/content/browser-fullScreenAndPointerLock.js

@@ -91,7 +91,7 @@ var PointerlockFsWarning = {
       let hostElem = this._element.querySelector(".pointerlockfswarning-domain");
       // Document's principal's URI has a host. Display a warning including it.
       let utils = {};
-      Cu.import("resource://gre/modules/DownloadUtils.jsm", utils);
+      ChromeUtils.import("resource://gre/modules/DownloadUtils.jsm", utils);
       hostElem.textContent = utils.DownloadUtils.getURIHost(uri.spec)[0];
     }