Bug 1542415: Part 4 - Always rebuild frameloaders on remoteness change in Fission windows. r=nika

Differential Revision: https://phabricator.services.mozilla.com/D44738

--HG--
extra : moz-landing-system : lando

browser/base/content/tabbrowser.js

@@ -1898,12 +1898,11 @@
       // Make sure the browser is destroyed so it unregisters from observer notifications
       aBrowser.destroy();
       // Only remove the node if we're not rebuilding the frameloader via nsFrameLoaderOwner.
-      if (
-        !Services.prefs.getBoolPref(
-          "fission.rebuild_frameloaders_on_remoteness_change",
-          false
-        )
-      ) {
+      let rebuildFrameLoaders =
+        Services.prefs.getBoolPref(
+          "fission.rebuild_frameloaders_on_remoteness_change"
+        ) || window.docShell.nsILoadContext.useRemoteSubframes;
+      if (!rebuildFrameLoaders) {
         aBrowser.remove();
       }
 
@@ -1948,12 +1947,7 @@
         aBrowser.removeAttribute("remoteType");
       }
 
-      if (
-        !Services.prefs.getBoolPref(
-          "fission.rebuild_frameloaders_on_remoteness_change",
-          false
-        )
-      ) {
+      if (!rebuildFrameLoaders) {
         parent.appendChild(aBrowser);
       } else {
         // This call actually switches out our frameloaders. Do this as late as

dom/media/test/mochitest.ini

@@ -706,7 +706,6 @@ support-files =
   hls/960x720_seg1.ts
 
 [test_access_control.html]
-fail-if = fission
 [test_arraybuffer.html]
 [test_aspectratio_mp4.html]
 [test_audio1.html]

dom/media/tests/mochitest/identity/mochitest.ini

@@ -42,7 +42,6 @@ scheme=https
 [test_peerConnection_asymmetricIsolation.html]
 scheme=https
 [test_loginNeeded.html]
-fail-if = fission
 support-files =
   /.well-known/idp-proxy/login.html
   /.well-known/idp-proxy/idp.sjs

dom/tests/mochitest/bugs/mochitest.ini

@@ -39,7 +39,6 @@ support-files =
   file1_bug414291.html
   file2_bug414291.html
 prefs =
-  fission.rebuild_frameloaders_on_remoteness_change=true
   plugin.load_flash_only=false
 
 [test_DOMWindowCreated_chromeonly.html]

dom/tests/mochitest/localstorage/mochitest.ini

@@ -18,8 +18,6 @@ support-files =
   frameLocalStorageSessionOnly.html
   file_tryAccessSessionStorage.html
   windowProxy.html
-prefs =
-  fission.rebuild_frameloaders_on_remoteness_change=true
 
 [test_brokenUTF-16.html]
 [test_bug600307-DBOps.html]

dom/tests/mochitest/sessionstorage/mochitest.ini

@@ -7,8 +7,6 @@ support-files =
   frameReplace.html
   interOriginSlave.js
   interOriginTest.js
-prefs =
-  fission.rebuild_frameloaders_on_remoteness_change=true
 
 [test_sessionStorageBase.html]
 [test_sessionStorageBaseSessionOnly.html]

dom/tests/mochitest/whatwg/mochitest.ini

@@ -15,8 +15,6 @@ support-files =
   postMessage_throw_helper.html
   postMessage_transfer_helper.html
   postMessage_userpass_helper.html
-prefs =
-  fission.rebuild_frameloaders_on_remoteness_change=true
 
 [test_bug477323.html]
 [test_document_scripts.html]

toolkit/components/remotebrowserutils/tests/browser/browser.ini

@@ -11,7 +11,7 @@ support-files =
 [browser_RemoteWebNavigation.js]
 skip-if = fission
 [browser_httpResponseProcessSelection.js]
-fail-if = fission
+skip-if = fission # BrowserTestUtils.browserLoaded call that spans a process switch
 [browser_httpCrossOriginOpenerPolicy.js]
 skip-if = fission
 [browser_httpToFileHistory.js]

toolkit/content/widgets/browser-custom-element.js

@@ -47,11 +47,12 @@
       //
       // Only do this when the rebuild frameloaders pref is off. This update isn't
       // required when we rebuild the frameloaders in the backend.
+      let rebuildFrameLoaders =
+        Services.prefs.getBoolPref(
+          "fission.rebuild_frameloaders_on_remoteness_change"
+        ) || this.ownerGlobal.docShell.nsILoadContext.useRemoteSubframes;
       if (
-        !Services.prefs.getBoolPref(
-          "fission.rebuild_frameloaders_on_remoteness_change",
-          false
-        ) &&
+        !rebuildFrameLoaders &&
         name === "remote" &&
         oldValue != newValue &&
         this.isConnectedAndReady