Revert 147328 - Current status of patch:

gpu/command_buffer/service/program_cache_lru_helper.cc

-// 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.
-
-#include "gpu/command_buffer/service/program_cache_lru_helper.h"
-
-namespace gpu {
-namespace gles2 {
-
-ProgramCacheLruHelper::ProgramCacheLruHelper() {}
-ProgramCacheLruHelper::~ProgramCacheLruHelper() {}
-
-void ProgramCacheLruHelper::Clear() {
-  location_map.clear();
-  queue.clear();
-}
-
-bool ProgramCacheLruHelper::IsEmpty() {
-  return queue.empty();
-}
-
-void ProgramCacheLruHelper::KeyUsed(const std::string& key) {
-  IteratorMap::iterator location_iterator = location_map.find(key);
-  if (location_iterator != location_map.end()) {
-    // already exists, erase it
-    queue.erase(location_iterator->second);
-  }
-  queue.push_front(key);
-  location_map[key] = queue.begin();
-}
-
-const std::string* ProgramCacheLruHelper::PeekKey() {
-  if (queue.empty()) {
-    return NULL;
-  }
-  return &queue.back();
-}
-
-void ProgramCacheLruHelper::PopKey() {
-  if (queue.empty()) {
-    return;
-  }
-  const std::string& last = queue.back();
-  location_map.erase(last);
-  queue.pop_back();
-}
-
-}  // namespace gpu
-}  // namespace gles2