Move FileWatcher from src/base/ to src/chrome/browser/ and switch

chrome/browser/file_watcher.h

 // Copyright (c) 2010 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.
 
 // This module provides a way to monitor a file for changes.
 
-#ifndef BASE_FILE_WATCHER_H_
-#define BASE_FILE_WATCHER_H_
+#ifndef CHROME_BROWSER_FILE_WATCHER_H_
+#define CHROME_BROWSER_FILE_WATCHER_H_
 
 #include "base/basictypes.h"
 #include "base/ref_counted.h"
+#include "chrome/browser/chrome_thread.h"
 
 class FilePath;
-class MessageLoop;
-
 // This class lets you register interest in changes on a file. The delegate
 // will get called whenever the file is changed, including created or deleted.
 // WARNING: To be able to get create/delete notifications and to work cross
 // platform, we actually listen for changes to the directory containing
 // the file.
 // WARNING: On OSX and Windows, the OS API doesn't tell us which file in the
 // directory changed.  We work around this by watching the file time, but this
 // can result in some extra notifications if we get other notifications within
 // 2s of the file having changed.
 class FileWatcher {
  public:
   class Delegate {
    public:
     virtual ~Delegate() {}
     virtual void OnFileChanged(const FilePath& path) = 0;
   };
 
   FileWatcher();
   ~FileWatcher() {}
 
   // Register interest in any changes on the file |path|.
-  // OnFileChanged will be called back for each change to the file.
-  // Any background operations will be ran on |backend_loop|, or inside Watch
-  // if |backend_loop| is NULL.  Note: The directory containing |path| must
-  // exist before you try to watch the file.
-  // Returns false on error.
-  bool Watch(const FilePath& path, Delegate* delegate,
-             MessageLoop* backend_loop) {
-    return impl_->Watch(path, delegate, backend_loop);
+  // OnFileChanged will be called back for each change to the file.  Any
+  // background operations will be ran on |backend_thread_id|.  Note: The
+  // directory containing |path| must exist before you try to watch the file.
+  // Returns false if the watch can't be added.
+  bool Watch(const FilePath& path, Delegate* delegate) {
+    DCHECK(ChromeThread::CurrentlyOn(ChromeThread::FILE));
+    return impl_->Watch(path, delegate);
   }
 
   // Used internally to encapsulate different members on different platforms.
-  class PlatformDelegate : public base::RefCounted<PlatformDelegate> {
+  class PlatformDelegate
+      : public base::RefCountedThreadSafe<PlatformDelegate,
+                                          ChromeThread::DeleteOnFileThread> {
    public:
-    virtual bool Watch(const FilePath& path, Delegate* delegate,
-                       MessageLoop* backend_loop) = 0;
+    virtual ~PlatformDelegate() {}
 
-   protected:
-    friend class base::RefCounted<PlatformDelegate>;
-
-    virtual ~PlatformDelegate() {}
+    virtual bool Watch(const FilePath& path, Delegate* delegate) = 0;
   };
 
  private:
   scoped_refptr<PlatformDelegate> impl_;
 
   DISALLOW_COPY_AND_ASSIGN(FileWatcher);
 };
 
-#endif  // BASE_FILE_WATCHER_H_
+#endif  // CHROME_BROWSER_FILE_WATCHER_H_