Require FilePathWatcher destructor to be called in sequence with Watch().

chrome/common/service_process_util_posix.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_COMMON_SERVICE_PROCESS_UTIL_POSIX_H_
 #define CHROME_COMMON_SERVICE_PROCESS_UTIL_POSIX_H_
 
 #include "chrome/common/service_process_util.h"
 
 #include <signal.h>
 
 #include <memory>
 
 #include "base/callback.h"
+#include "base/memory/ref_counted.h"
 #include "base/message_loop/message_loop.h"
+#include "base/single_thread_task_runner.h"
 #include "build/build_config.h"
 
 #if defined(OS_POSIX) && !defined(OS_MACOSX)
 #include "chrome/common/multi_process_lock.h"
 MultiProcessLock* TakeServiceRunningLock(bool waiting);
 #endif
 
 #if defined(OS_MACOSX)
 #include "base/files/file_path_watcher.h"
 #include "base/mac/scoped_cftyperef.h"
@@ skipping 24 matching lines @@
   ~ServiceProcessTerminateMonitor() override;
 
   // MessageLoopForIO::Watcher overrides
   void OnFileCanReadWithoutBlocking(int fd) override;
   void OnFileCanWriteWithoutBlocking(int fd) override;
 
  private:
   base::Closure terminate_task_;
 };
 
-struct ServiceProcessState::StateData
-    : public base::RefCountedThreadSafe<ServiceProcessState::StateData> {
+struct ServiceProcessState::StateData {
   StateData();
+  ~StateData();
 
   // WatchFileDescriptor needs to be set up by the thread that is going
   // to be monitoring it.
   void SignalReady(base::WaitableEvent* signal, bool* success);
 
 #if defined(OS_MACOSX)
   bool WatchExecutable();
 
   base::ScopedCFTypeRef<CFDictionaryRef> launchd_conf;
   base::FilePathWatcher executable_watcher;
-#endif  // OS_MACOSX
-#if defined(OS_POSIX) && !defined(OS_MACOSX)
+#else
   std::unique_ptr<MultiProcessLock> initializing_lock;
   std::unique_ptr<MultiProcessLock> running_lock;
 #endif
   std::unique_ptr<ServiceProcessTerminateMonitor> terminate_monitor;
   base::MessageLoopForIO::FileDescriptorWatcher watcher;
   int sockets[2];
   struct sigaction old_action;
   bool set_action;
 
- protected:
-  friend class base::RefCountedThreadSafe<ServiceProcessState::StateData>;
-  virtual ~StateData();
+  // The SingleThreadTaskRunner on which SignalReady and the destructor are
+  // invoked.
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner;
 };
 
 #endif  // CHROME_COMMON_SERVICE_PROCESS_UTIL_POSIX_H_