Bug 1393710 - Add thread name into NS_DebugBreak for better debugging. r=froydnj

MozReview-Commit-ID: AvqajMgtpuh

xpcom/threads/nsThreadManager.cpp

@@ -33,6 +33,12 @@ using namespace mozilla;
 static MOZ_THREAD_LOCAL(bool) sTLSIsMainThread;
 static MOZ_THREAD_LOCAL(PRThread*) gTlsCurrentVirtualThread;
 
+bool
+NS_IsMainThreadTLSInitialized()
+{
+  return sTLSIsMainThread.initialized();
+}
+
 bool
 NS_IsMainThread()
 {