Bug 1593545 - Disable DocumentChannel assertion in non-fission mode r…

…=mattwoodrow

Differential Revision: https://phabricator.services.mozilla.com/D52804

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

netwerk/protocol/http/nsHttpChannel.cpp

@@ -2593,6 +2593,15 @@ void nsHttpChannel::AssertNotDocumentChannel() {
     return;
   }
 
+#ifndef DEBUG
+  if (!StaticPrefs::fission_autostart()) {
+    // This assertion is firing in the wild (Bug 1593545) and its not clear
+    // why. Disable the assertion in non-fission non-debug configurations to
+    // avoid crashing user's browsers until we're done dogfooding fission.
+    return;
+  }
+#endif
+
   nsCOMPtr<nsIParentChannel> parentChannel;
   NS_QueryNotificationCallbacks(this, parentChannel);
   RefPtr<DocumentChannelParent> documentChannelParent =