Revert 147328 - Current status of patch:

gpu/command_buffer/service/program_cache_lru_helper.h

-// Copyright (c) 2012 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 GPU_COMMAND_BUFFER_SERVICE_PROGRAM_CACHE_LRU_HELPER_H_
-#define GPU_COMMAND_BUFFER_SERVICE_PROGRAM_CACHE_LRU_HELPER_H_
-
-#include <list>
-#include <string>
-
-#include "base/basictypes.h"
-#include "base/hash_tables.h"
-#include "gpu/gpu_export.h"
-
-namespace gpu {
-namespace gles2 {
-
-// LRU helper for the program cache, operates in O(1) time.
-// This class uses a linked list with a hash map.  Both copy their string keys,
-// so be mindful that keys you insert will be stored again twice in memory.
-class GPU_EXPORT ProgramCacheLruHelper {
- public:
-  ProgramCacheLruHelper();
-  ~ProgramCacheLruHelper();
-
-  // clears the lru queue
-  void Clear();
-  // returns true if the lru queue is empty
-  bool IsEmpty();
-  // inserts or refreshes a key in the queue
-  void KeyUsed(const std::string& key);
-  // Peeks at the next key.  Use IsEmpty() first (if the queue is empty then
-  // null is returned).
-  const std::string* PeekKey();
-  // evicts the next key from the queue.
-  void PopKey();
-
- private:
-  typedef std::list<std::string> StringList;
-  typedef base::hash_map<std::string,
-                         StringList::iterator> IteratorMap;
-  StringList queue;
-  IteratorMap location_map;
-
-  DISALLOW_COPY_AND_ASSIGN(ProgramCacheLruHelper);
-};
-
-}  // namespace gles2
-}  // namespace gpu
-
-#endif  // GPU_COMMAND_BUFFER_SERVICE_PROGRAM_CACHE_LRU_HELPER_H_