Bug 1613147 - Console API on worker dispatches messages to the main-thread behind prefs, r=asuth

Differential Revision: https://phabricator.services.mozilla.com/D61578

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

dom/console/Console.cpp

@@ -1573,9 +1573,11 @@ void Console::MethodInternal(JSContext* aCx, MethodName aMethodName,
   // We do this only in workers for now.
   NotifyHandler(aCx, aData, callData);
 
-  RefPtr<ConsoleCallDataWorkerRunnable> runnable =
-      new ConsoleCallDataWorkerRunnable(this, callData);
-  Unused << NS_WARN_IF(!runnable->Dispatch(aCx));
+  if (StaticPrefs::dom_worker_console_dispatch_events_to_main_thread()) {
+    RefPtr<ConsoleCallDataWorkerRunnable> runnable =
+        new ConsoleCallDataWorkerRunnable(this, callData);
+    Unused << NS_WARN_IF(!runnable->Dispatch(aCx));
+  }
 }
 
 // We store information to lazily compute the stack in the reserved slots of

modules/libpref/init/StaticPrefList.yaml

@@ -2910,6 +2910,13 @@
   value: true
   mirror: always
 
+# Enables the dispatching of console log events from worker threads to the
+# main-thread.
+- name: dom.worker.console.dispatch_events_to_main_thread
+  type: RelaxedAtomicBool
+  value: true
+  mirror: always
+
 - name: dom.worklet.enabled
   type: bool
   value: false