Bug 1139678 - (Part 2) Update non-reader-able test URL in browser_readerMode.js. r=Gijs

--HG--
extra : rebase_source : f37e89e44dbaaf1df46529f66b75b0c7d378b465

browser/base/content/content.js

@@ -490,7 +490,7 @@ let AboutReaderListener = {
   receiveMessage: function(message) {
     switch (message.name) {
       case "Reader:ParseDocument":
-        this._articlePromise = ReaderMode.parseDocument(content.document);
+        this._articlePromise = ReaderMode.parseDocument(content.document).catch(Cu.reportError);
         content.document.location = "about:reader?url=" + encodeURIComponent(message.data.url);
         break;
     }

browser/base/content/test/general/browser_readerMode.js

@@ -71,7 +71,7 @@ add_task(function* () {
 
   // Load a new tab that is NOT reader-able.
   let newTab = gBrowser.selectedTab = gBrowser.addTab();
-  yield promiseTabLoadEvent(newTab, TEST_PATH + "download_page.html");
+  yield promiseTabLoadEvent(newTab, "about:robots");
   yield promiseWaitForCondition(() => readerButton.hidden);
   is_element_hidden(readerButton, "Reader mode button is not present on a non-reader-able page");