Backed out 2 changesets (bug 1689684, bug 1689664) for assertion failure at nsSHistory.cpp on fission CLOSED TREE

Backed out changeset 506586ec7b20 (bug 1689684)
Backed out changeset f7c03240d0cc (bug 1689664)

docshell/test/browser/browser.ini

@@ -93,6 +93,7 @@ skip-if =
 [browser_bug1309900_crossProcessHistoryNavigation.js]
 [browser_bug1328501.js]
 [browser_bug1347823.js]
+fail-if = sessionHistoryInParent
 [browser_bug134911.js]
 [browser_bug1415918_beforeunload_options.js]
 [browser_bug1622420.js]

docshell/test/browser/browser_bug1347823.js

@@ -7,11 +7,7 @@
 add_task(async function testValidCache() {
   // Make an unrealistic large timeout.
   await SpecialPowers.pushPrefEnv({
-    set: [
-      ["browser.sessionhistory.contentViewerTimeout", 86400],
-      // If Fission is disabled, the pref is no-op.
-      ["fission.bfcacheInParent", true],
-    ],
+    set: [["browser.sessionhistory.contentViewerTimeout", 86400]],
   });
 
   await BrowserTestUtils.withNewTab(
@@ -44,11 +40,7 @@ add_task(async function testValidCache() {
 add_task(async function testExpiredCache() {
   // Make bfcache timeout in 1 sec.
   await SpecialPowers.pushPrefEnv({
-    set: [
-      ["browser.sessionhistory.contentViewerTimeout", 1],
-      // If Fission is disabled, the pref is no-op.
-      ["fission.bfcacheInParent", true],
-    ],
+    set: [["browser.sessionhistory.contentViewerTimeout", 1]],
   });
 
   await BrowserTestUtils.withNewTab(

docshell/test/navigation/mochitest.ini

@@ -120,6 +120,7 @@ skip-if =
   (debug && e10s)  # bug 1263213
   (os == 'mac' && os_version == '10.14')  # Bug 1548821
 [test_performance_navigation.html]
+skip-if = fission # bug 1666602
 [test_sessionhistory.html]
 skip-if = verify && (os == 'mac') && debug && webrender # Hit MOZ_CRASH(Shutdown too long, probably frozen, causing a crash.) bug 1677545
 [test_dynamic_frame_forward_back.html]

docshell/test/navigation/test_performance_navigation.html

@@ -29,10 +29,7 @@ bc.onmessage = function(msgEvent) {
 };
 
 function runTest() {
-  // If Fission is disabled, the pref is no-op.
-  SpecialPowers.pushPrefEnv({set: [["fission.bfcacheInParent", true]]}, () => {
-    window.open("test_bug145971.html", "", "width=360,height=480,noopener");
-  });
+  window.open("test_bug145971.html", "", "width=360,height=480,noopener");
 }
 
 </script>