base: Fix DCHECK when thread creation fails

base/message_loop/message_loop_unittest.cc

Index: base/message_loop/message_loop_unittest.cc
diff --git a/base/message_loop/message_loop_unittest.cc b/base/message_loop/message_loop_unittest.cc
index 8b7a84d46df0bedbce2b7a74a68eefcb54268263..1a3a92570074c5a476259c4255d3fe20cf60b86e 100644
--- a/base/message_loop/message_loop_unittest.cc
+++ b/base/message_loop/message_loop_unittest.cc
@@ -1041,4 +1041,15 @@ TEST(MessageLoopTest, OriginalRunnerWorks) {
   EXPECT_EQ(1, foo->test_count());
 }
 
+TEST(MessageLoopTest, DeleteUnboundLoop) {
+  // It should be possible to delete an unbound message loop on a thread which
+  // already has another active loop. This happens when thread creation fails.
+  MessageLoop loop;
+  scoped_ptr<MessageLoop> unbound_loop(MessageLoop::CreateUnbound(
+      MessageLoop::TYPE_DEFAULT, MessageLoop::MessagePumpFactoryCallback()));
+  unbound_loop.reset();
+  EXPECT_EQ(&loop, MessageLoop::current());
+  EXPECT_EQ(loop.task_runner(), ThreadTaskRunnerHandle::Get());
+}
+
 }  // namespace base