Split file_observers.h into three files for each class

chrome/browser/sync_file_system/local/local_file_change_tracker.h

 // Copyright 2013 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_BROWSER_SYNC_FILE_SYSTEM_LOCAL_LOCAL_FILE_CHANGE_TRACKER_H_
 #define CHROME_BROWSER_SYNC_FILE_SYSTEM_LOCAL_LOCAL_FILE_CHANGE_TRACKER_H_
 
 #include <deque>
 #include <map>
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/synchronization/lock.h"
 #include "chrome/browser/sync_file_system/file_change.h"
 #include "chrome/browser/sync_file_system/sync_status_code.h"
-#include "webkit/browser/fileapi/file_observers.h"
+#include "webkit/browser/fileapi/file_change_observer.h"
 #include "webkit/browser/fileapi/file_system_url.h"
+#include "webkit/browser/fileapi/file_update_observer.h"
 
 namespace base {
 class SequencedTaskRunner;
 }
 
 namespace fileapi {
 class FileSystemContext;
 class FileSystemURL;
 }
 
@@ skipping 129 matching lines @@
   // This can be accessed on any threads (with num_changes_lock_).
   int64 num_changes_;
   mutable base::Lock num_changes_lock_;
 
   DISALLOW_COPY_AND_ASSIGN(LocalFileChangeTracker);
 };
 
 }  // namespace sync_file_system
 
 #endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_LOCAL_LOCAL_FILE_CHANGE_TRACKER_H_