Bug 1351874 - Dispatch shutdown runnable to CDMParent rather than null. r=gerald

MozReview-Commit-ID: BE5OgrgbvAT

--HG--
extra : rebase_source : 68c2538e2de42caa0b3e98b03c47bbd01539049b

dom/media/gmp/ChromiumCDMProxy.cpp

@@ -356,7 +356,7 @@ ChromiumCDMProxy::Shutdown()
   }
   if (cdm) {
     nsCOMPtr<nsIRunnable> task =
-      NewRunnableMethod(mCDM, &gmp::ChromiumCDMParent::Shutdown);
+      NewRunnableMethod(cdm, &gmp::ChromiumCDMParent::Shutdown);
     mGMPThread->Dispatch(task.forget());
   }
 }