1 files changed, 3 insertions, 4 deletions
diff --git a/dom/events/Event.cpp b/dom/events/Event.cpp
index 7e19cd74d..4e39675da 100755
--- a/dom/events/Event.cpp
+++ b/dom/events/Event.cpp
@@ -1146,15 +1146,14 @@ Event::TimeStampImpl() const
     return perf->GetDOMTiming()->TimeStampToDOMHighRes(mEvent->mTimeStamp);
   }
 
-  // For dedicated workers, we should make times relative to the navigation
-  // start of the document that created the worker, which is the same as the
-  // timebase for performance.now().
+  // For dedicated workers, we should make times relative to the creation time
+  // of the worker, which is the same as the timebase for performance.now().
   workers::WorkerPrivate* workerPrivate =
     workers::GetCurrentThreadWorkerPrivate();
   MOZ_ASSERT(workerPrivate);
 
   TimeDuration duration =
-    mEvent->mTimeStamp - workerPrivate->NowBaseTimeStamp();
+    mEvent->mTimeStamp - workerPrivate->CreationTimeStamp();
   return duration.ToMilliseconds();
 }