Delete watcher on IO thread in MessagePumpLibeventTest.QuitWatcher.

base/message_loop/message_pump_libevent_unittest.cc

Index: base/message_loop/message_pump_libevent_unittest.cc
diff --git a/base/message_loop/message_pump_libevent_unittest.cc b/base/message_loop/message_pump_libevent_unittest.cc
index 424621109aa6101053a486b61ad861c6c6480872..e911905abd7b489b47254a7195f6315701b422e9 100644
--- a/base/message_loop/message_pump_libevent_unittest.cc
+++ b/base/message_loop/message_pump_libevent_unittest.cc
@@ -246,7 +246,7 @@ TEST_F(MessagePumpLibeventTest, QuitWatcher) {
   MessagePumpLibevent::FileDescriptorWatcher controller;
   QuitWatcher delegate(&controller, &run_loop);
   WaitableEvent event(false /* manual_reset */, false /* initially_signaled */);
-  WaitableEventWatcher watcher;
+  scoped_ptr<WaitableEventWatcher> watcher(new WaitableEventWatcher);
 
   // Tell the pump to watch the pipe.
   pump->WatchFileDescriptor(pipefds_[0], false, MessagePumpLibevent::WATCH_READ,
@@ -258,13 +258,17 @@ TEST_F(MessagePumpLibeventTest, QuitWatcher) {
       Bind(&WriteFDWrapper, pipefds_[1], &buf, 1);
   io_loop()->PostTask(FROM_HERE,
                       Bind(IgnoreResult(&WaitableEventWatcher::StartWatching),
-                           Unretained(&watcher), &event, write_fd_task));
+                           Unretained(watcher.get()), &event, write_fd_task));
 
   // Queue |event| to signal on |loop|.
   loop.PostTask(FROM_HERE, Bind(&WaitableEvent::Signal, Unretained(&event)));
 
   // Now run the MessageLoop.
   run_loop.Run();
+
+  // StartWatching can move |watcher| to IO thread. Release on IO thread.
+  io_loop()->PostTask(FROM_HERE, Bind(&WaitableEventWatcher::StopWatching,
+                                      Owned(watcher.release())));
 }
 
 }  // namespace