Bug 1634272 - Don't use DocumentChannel for about:newtab r=mattwoodrow

To avoid this regression we can avoid DocumentChannel because it'll probably
be fixed by Bug 1626507.

Differential Revision: https://phabricator.services.mozilla.com/D77638

browser/base/content/test/tabs/browser.ini

@@ -59,6 +59,7 @@ skip-if = os == 'mac' # Skipped because macOS keyboard support requires changing
 [browser_multiselect_tabs_using_selectedTabs.js]
 [browser_multiselect_tabs_using_Shift_and_Ctrl.js]
 [browser_multiselect_tabs_using_Shift.js]
+[browser_navigate_home_focuses_addressbar.js]
 [browser_navigatePinnedTab.js]
 [browser_new_file_whitelisted_http_tab.js]
 skip-if = !e10s # Test only relevant for e10s.

browser/base/content/test/tabs/browser_navigate_home_focuses_addressbar.js

@@ -0,0 +1,16 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+
+const TEST_HTTP = httpURL("dummy_page.html");
+
+// Test for Bug 1634272
+add_task(async function() {
+  await BrowserTestUtils.withNewTab(TEST_HTTP, async function(browser) {
+    info("Tab ready");
+
+    document.getElementById("home-button").click();
+    await BrowserTestUtils.browserLoaded(browser, false, HomePage.get());
+    is(gURLBar.value, "", "URL bar should be empty");
+    ok(gURLBar.focused, "URL bar should be focused");
+  });
+});

toolkit/modules/E10SUtils.jsm

@@ -135,6 +135,7 @@ const kDocumentChannelDeniedURIs = [
   "about:blank",
   "about:crashcontent",
   "about:newtab",
+  "about:home",
   "about:printpreview",
 ];