base: Fix DCHECK when thread creation fails

base/message_loop/message_loop.h

Index: base/message_loop/message_loop.h
diff --git a/base/message_loop/message_loop.h b/base/message_loop/message_loop.h
index 364d04d429870f2611705490a0c56b9414d8d6ad..8ef8d6a21fff5ffb914ddcc7a1e7202acc4fa9cd 100644
--- a/base/message_loop/message_loop.h
+++ b/base/message_loop/message_loop.h
@@ -11,6 +11,7 @@
 #include "base/base_export.h"
 #include "base/callback_forward.h"
 #include "base/debug/task_annotator.h"
+#include "base/gtest_prod_util.h"
 #include "base/location.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
@@ -403,6 +404,7 @@ class BASE_EXPORT MessageLoop : public MessagePump::Delegate {
   friend class internal::IncomingTaskQueue;
   friend class ScheduleWorkTest;
   friend class Thread;
+  FRIEND_TEST_ALL_PREFIXES(MessageLoopTest, DeleteUnboundLoop);
 
   using MessagePumpFactoryCallback = Callback<scoped_ptr<MessagePump>()>;