Remove destruction observer from base::FilePathWatcherKQueue.

base/files/file_path_watcher_kqueue.h

 // Copyright 2014 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 BASE_FILES_FILE_PATH_WATCHER_KQUEUE_H_
 #define BASE_FILES_FILE_PATH_WATCHER_KQUEUE_H_
 
 #include <sys/event.h>
 
 #include <memory>
 #include <vector>
 
 #include "base/files/file_descriptor_watcher_posix.h"
 #include "base/files/file_path.h"
 #include "base/files/file_path_watcher.h"
 #include "base/macros.h"
-#include "base/message_loop/message_loop.h"
 #include "base/single_thread_task_runner.h"
 
 namespace base {
 
 // Mac-specific file watcher implementation based on kqueue.
 // The Linux and Windows versions are able to detect:
 // - file creation/deletion/modification in a watched directory
 // - file creation/deletion/modification for a watched file
 // - modifications to the paths to a watched object that would affect the
 //   object such as renaming/attibute changes etc.
 // The kqueue implementation will handle all of the items in the list above
 // except for detecting modifications to files in a watched directory. It will
 // detect the creation and deletion of files, just not the modification of
 // files. It does however detect the attribute changes that the FSEvents impl
 // would miss.
-class FilePathWatcherKQueue : public FilePathWatcher::PlatformDelegate,
-                              public MessageLoop::DestructionObserver {
+class FilePathWatcherKQueue : public FilePathWatcher::PlatformDelegate {
  public:
   FilePathWatcherKQueue();
 
-  // MessageLoop::DestructionObserver overrides.
-  void WillDestroyCurrentMessageLoop() override;
-
   // FilePathWatcher::PlatformDelegate overrides.
   bool Watch(const FilePath& path,
              bool recursive,
              const FilePathWatcher::Callback& callback) override;
   void Cancel() override;
 
  protected:
   ~FilePathWatcherKQueue() override;
 
  private:
   class EventData {
    public:
     EventData(const FilePath& path, const FilePath::StringType& subdir)
         : path_(path), subdir_(subdir) { }
     FilePath path_;  // Full path to this item.
     FilePath::StringType subdir_;  // Path to any sub item.
   };
 
   typedef std::vector<struct kevent> EventVector;
 
   // Called when data is available in |kqueue_|.
   void OnKQueueReadable();
 
-  // Can only be called on |io_task_runner_|'s thread.
-  void CancelOnMessageLoopThread();
-
   // Returns true if the kevent values are error free.
   bool AreKeventValuesValid(struct kevent* kevents, int count);
 
   // Respond to a change of attributes of the path component represented by
   // |event|. Sets |target_file_affected| to true if |target_| is affected.
   // Sets |update_watches| to true if |events_| need to be updated.
   void HandleAttributesChange(const EventVector::iterator& event,
                               bool* target_file_affected,
                               bool* update_watches);
 
@@ skipping 50 matching lines @@
   // Throughout the lifetime of this, OnKQueueReadable() will be called when
   // data is available in |kqueue_|.
   std::unique_ptr<FileDescriptorWatcher::Controller> kqueue_watch_controller_;
 
   DISALLOW_COPY_AND_ASSIGN(FilePathWatcherKQueue);
 };
 
 }  // namespace base
 
 #endif  // BASE_FILES_FILE_PATH_WATCHER_KQUEUE_H_