Bug 1465294 Part 16 - Support web workers when recording/replaying, r=smaug.

dom/workers/RuntimeService.cpp

@@ -576,6 +576,13 @@ InterruptCallback(JSContext* aCx)
   WorkerPrivate* worker = GetWorkerPrivateFromContext(aCx);
   MOZ_ASSERT(worker);
 
+  // As with the main thread, the interrupt callback is triggered
+  // non-deterministically when recording/replaying, so return early to avoid
+  // performing any recorded events.
+  if (recordreplay::IsRecordingOrReplaying()) {
+    return true;
+  }
+
   // Now is a good time to turn on profiling if it's pending.
   PROFILER_JS_INTERRUPT_CALLBACK();
 
@@ -965,6 +972,11 @@ public:
         NS_WARNING("failed to set workerCx's default locale");
       }
     }
+
+    // Cycle collections must occur at consistent points when recording/replaying.
+    if (recordreplay::IsRecordingOrReplaying()) {
+      recordreplay::RegisterTrigger(this, [=]() { nsCycleCollector_collect(nullptr); });
+    }
   }
 
   void Shutdown(JSContext* cx) override
@@ -979,6 +991,10 @@ public:
   ~WorkerJSRuntime()
   {
     MOZ_COUNT_DTOR_INHERITED(WorkerJSRuntime, CycleCollectedJSRuntime);
+
+    if (recordreplay::IsRecordingOrReplaying()) {
+      recordreplay::UnregisterTrigger(this);
+    }
   }
 
   virtual void
@@ -1015,9 +1031,13 @@ public:
     mWorkerPrivate->AssertIsOnWorkerThread();
 
     if (aStatus == JSGC_END) {
+      if (recordreplay::IsRecordingOrReplaying()) {
+        recordreplay::ActivateTrigger(this);
+      } else {
         nsCycleCollector_collect(nullptr);
       }
     }
+  }
 
 private:
   WorkerPrivate* mWorkerPrivate;