use setTimeout for the watchdog associated to the init message

lib/frame-tree/frame-tree.js

@@ -18,7 +18,7 @@
  *   along with SingleFile.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-/* global window, top, document, addEventListener, docHelper, timeout, MessageChannel, superFetch, fetch, TextDecoder, DOMParser, lazyLoader */
+/* global window, top, document, addEventListener, docHelper, timeout, MessageChannel, superFetch, fetch, TextDecoder, DOMParser, lazyLoader, setTimeout */
 
 this.frameTree = this.frameTree || (() => {
 
@@ -139,7 +139,7 @@ this.frameTree = this.frameTree || (() => {
 			} catch (error) {
 				/* ignored */
 			}
-			timeout.set(async () => {
+			setTimeout(async () => {
 				let frameDoc;
 				if (frameElement.src && frameElement.src.match(PREFIX_VALID_FRAME_URL)) {
 					frameDoc = await getFrameDoc(frameElement.src, parentWindowId, options);