Bug 1351526 - Label runnables in dom/media/platforms/wmf/WMFVideoMFTManager.cpp; r=jwwang

MozReview-Commit-ID: 9vtEKRgNnI6

--HG--
extra : rebase_source : 9bd7212c6a7f7606bcf7a5877d6e14a21e747114

dom/media/platforms/wmf/WMFVideoMFTManager.cpp

@@ -157,8 +157,9 @@ WMFVideoMFTManager::~WMFVideoMFTManager()
     Telemetry::Accumulate(Telemetry::HistogramID::VIDEO_MFT_OUTPUT_NULL_SAMPLES,
                           telemetry);
   });
-  // Non-DocGroup version of AbstractThread::MainThread is fine for Telemetry.
-  AbstractThread::MainThread()->Dispatch(task.forget());
+  SystemGroup::Dispatch("~WMFVideoMFTManager::report_telemetry",
+                        TaskCategory::Other,
+                        task.forget());
 }
 
 const GUID&