Reduce usage of MessageLoopProxy in base/

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 <vector>
 
 #include "base/files/file_path.h"
 #include "base/files/file_path_watcher.h"
 #include "base/message_loop/message_loop.h"
-#include "base/message_loop/message_loop_proxy.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
@@ skipping 27 matching lines @@
   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;
 
-  // Can only be called on |io_message_loop_|'s thread.
+  // Can only be called on |io_task_runner_|'s thread.
   virtual void CancelOnMessageLoopThread() override;
 
   // 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,
@@ skipping 38 matching lines @@
   // Returns true if kevent has open file descriptor.
   static bool IsKeventFileDescriptorOpen(const struct kevent& event) {
     return event.ident != kNoFileDescriptor;
   }
 
   static EventData* EventDataForKevent(const struct kevent& event) {
     return reinterpret_cast<EventData*>(event.udata);
   }
 
   EventVector events_;
-  scoped_refptr<base::MessageLoopProxy> io_message_loop_;
+  scoped_refptr<base::SequencedTaskRunner> io_task_runner_;
   MessageLoopForIO::FileDescriptorWatcher kqueue_watcher_;
   FilePathWatcher::Callback callback_;
   FilePath target_;
   int kqueue_;
 
   DISALLOW_COPY_AND_ASSIGN(FilePathWatcherKQueue);
 };
 
 }  // namespace base
 
 #endif  // BASE_FILES_FILE_PATH_WATCHER_KQUEUE_H_