Bug 1359309. P2 - dump the name of the TaskQueue when Dispatch() fails. r=jya

MozReview-Commit-ID: AqGviaekwRa

--HG--
extra : rebase_source : 03249fa43e7fde436d1e56ef21a9a5df66e941be
extra : intermediate-source : f50b5740178e39509b85b4cf216aca0ab45de821
extra : source : 86da182d4b06bd164ead844b164e602b58b93ffa

xpcom/threads/TaskQueue.h

@@ -69,7 +69,11 @@ public:
     {
       MonitorAutoLock mon(mQueueMonitor);
       nsresult rv = DispatchLocked(/* passed by ref */r, aFailureHandling, aReason);
-      MOZ_DIAGNOSTIC_ASSERT(aFailureHandling == DontAssertDispatchSuccess || NS_SUCCEEDED(rv));
+#if defined(DEBUG) || !defined(RELEASE_OR_BETA) || defined(EARLY_BETA_OR_EARLIER)
+      if (NS_FAILED(rv) && aFailureHandling == AssertDispatchSuccess) {
+        MOZ_CRASH_UNSAFE_PRINTF("%s: Dispatch failed. rv=%x", mName, uint32_t(rv));
+      }
+#endif
       Unused << rv;
     }
     // If the ownership of |r| is not transferred in DispatchLocked() due to