Remove SchedulerUniqueStack

base/task_scheduler/scheduler_unique_stack.h

-// Copyright 2016 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_TASK_SCHEDULER_SCHEDULER_UNIQUE_STACK_H_
-#define BASE_TASK_SCHEDULER_SCHEDULER_UNIQUE_STACK_H_
-
-#include <stddef.h>
-
-#include <algorithm>
-#include <vector>
-
-#include "base/logging.h"
-#include "base/macros.h"
-
-namespace base {
-namespace internal {
-
-// A stack that supports removal of arbitrary values and doesn't allow multiple
-// insertions of the same value. This class is NOT thread-safe.
-template <typename T>
-class SchedulerUniqueStack {
- public:
-  SchedulerUniqueStack();
-  ~SchedulerUniqueStack();
-
-  // Inserts |val| at the top of the stack. |val| must not already be on the
-  // stack.
-  void Push(const T& val);
-
-  // Removes the top value from the stack and returns it. Cannot be called on an
-  // empty stack.
-  T Pop();
-
-  // Removes |val| from the stack.
-  void Remove(const T& val);
-
-  // Returns the number of values on the stack.
-  size_t Size() const;
-
-  // Returns true if the stack is empty.
-  bool Empty() const;
-
- private:
-  std::vector<T> stack_;
-
-  DISALLOW_COPY_AND_ASSIGN(SchedulerUniqueStack);
-};
-
-template <typename T>
-SchedulerUniqueStack<T>::SchedulerUniqueStack() = default;
-
-template <typename T>
-SchedulerUniqueStack<T>::~SchedulerUniqueStack() = default;
-
-template <typename T>
-void SchedulerUniqueStack<T>::Push(const T& val) {
-  DCHECK(std::find(stack_.begin(), stack_.end(), val) == stack_.end())
-      << "Value already on stack";
-  stack_.push_back(val);
-}
-
-template <typename T>
-T SchedulerUniqueStack<T>::Pop() {
-  DCHECK(!stack_.empty());
-  const T val = stack_.back();
-  stack_.pop_back();
-  return val;
-}
-
-template <typename T>
-void SchedulerUniqueStack<T>::Remove(const T& val) {
-  auto it = std::find(stack_.begin(), stack_.end(), val);
-  if (it != stack_.end())
-    stack_.erase(it);
-}
-
-template <typename T>
-size_t SchedulerUniqueStack<T>::Size() const {
-  return stack_.size();
-}
-
-template <typename T>
-bool SchedulerUniqueStack<T>::Empty() const {
-  return stack_.empty();
-}
-
-}  // namespace internal
-}  // namespace base
-
-#endif  // BASE_TASK_SCHEDULER_SCHEDULER_UNIQUE_STACK_H_