base: Cleanup class/struct forward declarations

base/files/file_proxy.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_PROXY_H_
 #define BASE_FILES_FILE_PROXY_H_
 
 #include <stdint.h>
 
 #include "base/base_export.h"
 #include "base/callback_forward.h"
 #include "base/files/file.h"
 #include "base/files/file_path.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 
-namespace tracked_objects {
-class Location;
-};
-
 namespace base {
 
 class TaskRunner;
 class Time;
 
 // This class provides asynchronous access to a File. All methods follow the
 // same rules of the equivalent File method, as they are implemented by bouncing
 // the operation to File using a TaskRunner.
 //
 // This class performs automatic proxying to close the underlying file at
@@ skipping 108 matching lines @@
   TaskRunner* task_runner() { return task_runner_.get(); }
 
   scoped_refptr<TaskRunner> task_runner_;
   File file_;
   DISALLOW_COPY_AND_ASSIGN(FileProxy);
 };
 
 }  // namespace base
 
 #endif  // BASE_FILES_FILE_PROXY_H_