Backed out 2 changesets (bug 1703291) for bc failures on BrowsingContext.cpp . CLOSED TREE

Backed out changeset 4d216ecbacd9 (bug 1703291)
Backed out changeset 51d244d886aa (bug 1703291)

docshell/shistory/nsSHistory.h

@@ -178,11 +178,7 @@ class nsSHistory : public mozilla::LinkedListElement<nsSHistory>,
   void SetHasOngoingUpdate(bool aVal) { mHasOngoingUpdate = aVal; }
 
   void SetBrowsingContext(mozilla::dom::BrowsingContext* aRootBC) {
-    if (mRootBC == aRootBC) {
-      return;
-    }
     mRootBC = aRootBC;
-    UpdateRootBrowsingContextState();
   }
 
   int32_t GetIndexForReplace() {

dom/base/test/test_window_close.html

@@ -41,9 +41,6 @@
     var loadTypes = ["withouthistory", "withhistory"];
 
     async function start() {
-      // If Fission is disabled, the pref is no-op.
-      await SpecialPowers.pushPrefEnv({set: [["fission.bfcacheInParent", true]]});
-
       for (let test of tests) {
         await SpecialPowers.pushPrefEnv({ set: [["dom.allow_scripts_to_close_windows", false]]});
         if (test.type == windowopen) {
@@ -80,6 +77,7 @@
           }
         }
       }
+
       SimpleTest.finish();
     }