Bug 1597435 - part 2: Fix uses of nsIDocShellTreeItem in nsGlobalWindowOuter::SetInitialPrincipalToSubject. r=farre

Differential Revision: https://phabricator.services.mozilla.com/D69011

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

dom/base/nsGlobalWindowOuter.cpp

@@ -1754,7 +1754,7 @@ void nsGlobalWindowOuter::SetInitialPrincipalToSubject(
   // nsAppShellService::JustCreateTopWindow
   if (nsContentUtils::IsExpandedPrincipal(newWindowPrincipal) ||
       (newWindowPrincipal->IsSystemPrincipal() &&
-       GetDocShell()->ItemType() != nsIDocShellTreeItem::typeChrome)) {
+       GetBrowsingContext()->IsContent())) {
     newWindowPrincipal = nullptr;
   }
 

xpfe/appshell/nsAppShellService.cpp

@@ -700,7 +700,7 @@ nsresult nsAppShellService::JustCreateTopWindow(
   }
 
   if (nsDocShell* docShell = nsDocShell::Cast(window->GetDocShell())) {
-    MOZ_ASSERT(docShell->ItemType() == nsIDocShellTreeItem::typeChrome);
+    MOZ_ASSERT(docShell->GetBrowsingContext()->IsChrome());
 
     docShell->SetPrivateBrowsing(isPrivateBrowsingWindow);
     docShell->SetRemoteTabs(aChromeMask &