Split file_observers.h into three files for each class

chrome/browser/sync_file_system/syncable_file_system_util.cc

 // 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.
 
 #include "chrome/browser/sync_file_system/syncable_file_system_util.h"
 
 #include "base/command_line.h"
 #include "base/location.h"
 #include "webkit/browser/fileapi/external_mount_points.h"
-#include "webkit/browser/fileapi/file_observers.h"
 #include "webkit/browser/fileapi/file_system_context.h"
 #include "webkit/browser/fileapi/sandbox_file_system_backend.h"
 #include "webkit/common/fileapi/file_system_util.h"
 
 using fileapi::ExternalMountPoints;
 using fileapi::FileSystemContext;
 using fileapi::FileSystemURL;
 
 namespace sync_file_system {
 
@@ skipping 107 matching lines @@
   DCHECK(IsSyncFSDirectoryOperationEnabled());
   SetEnableSyncFSDirectoryOperation(was_enabled_);
 }
 
 void RunSoon(const tracked_objects::Location& from_here,
              const base::Closure& callback) {
   base::MessageLoop::current()->PostTask(from_here, callback);
 }
 
 }  // namespace sync_file_system