Remove SchedulerUniqueStack

This code is unreferenced.

BUG=553459

Review-Url: https://codereview.chromium.org/2068803002
Cr-Commit-Position: refs/heads/master@{#399774}


CrOS-Libchrome-Original-Commit: 393d42a00dc3b5c09989e233ce679bd918204148
diff --git a/base/task_scheduler/scheduler_unique_stack.h b/base/task_scheduler/scheduler_unique_stack.h
deleted file mode 100644
index 4f9ce14..0000000
--- a/base/task_scheduler/scheduler_unique_stack.h
+++ /dev/null
@@ -1,91 +0,0 @@
-// 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_
diff --git a/base/task_scheduler/scheduler_unique_stack_unittest.cc b/base/task_scheduler/scheduler_unique_stack_unittest.cc
deleted file mode 100644
index 8ef72dd..0000000
--- a/base/task_scheduler/scheduler_unique_stack_unittest.cc
+++ /dev/null
@@ -1,110 +0,0 @@
-// 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.
-
-#include "base/task_scheduler/scheduler_unique_stack.h"
-
-#include "base/task_scheduler/test_utils.h"
-#include "testing/gtest/include/gtest/gtest.h"
-
-namespace base {
-namespace internal {
-
-// Verify that Push() and Pop() add/remove values in FIFO order.
-TEST(TaskSchedulerUniqueStackTest, PushPop) {
-  SchedulerUniqueStack<int> stack;
-  EXPECT_TRUE(stack.Empty());
-  EXPECT_EQ(0U, stack.Size());
-
-  stack.Push(1);
-  EXPECT_FALSE(stack.Empty());
-  EXPECT_EQ(1U, stack.Size());
-
-  stack.Push(2);
-  EXPECT_FALSE(stack.Empty());
-  EXPECT_EQ(2U, stack.Size());
-
-  stack.Push(3);
-  EXPECT_FALSE(stack.Empty());
-  EXPECT_EQ(3U, stack.Size());
-
-  EXPECT_EQ(3, stack.Pop());
-  EXPECT_FALSE(stack.Empty());
-  EXPECT_EQ(2U, stack.Size());
-
-  stack.Push(3);
-  EXPECT_FALSE(stack.Empty());
-  EXPECT_EQ(3U, stack.Size());
-
-  EXPECT_EQ(3, stack.Pop());
-  EXPECT_FALSE(stack.Empty());
-  EXPECT_EQ(2U, stack.Size());
-
-  EXPECT_EQ(2, stack.Pop());
-  EXPECT_FALSE(stack.Empty());
-  EXPECT_EQ(1U, stack.Size());
-
-  EXPECT_EQ(1, stack.Pop());
-  EXPECT_TRUE(stack.Empty());
-  EXPECT_EQ(0U, stack.Size());
-}
-
-// Verify that a value can be removed by Remove().
-TEST(TaskSchedulerUniqueStackTest, Remove) {
-  SchedulerUniqueStack<int> stack;
-  EXPECT_TRUE(stack.Empty());
-  EXPECT_EQ(0U, stack.Size());
-
-  stack.Push(1);
-  EXPECT_FALSE(stack.Empty());
-  EXPECT_EQ(1U, stack.Size());
-
-  stack.Push(2);
-  EXPECT_FALSE(stack.Empty());
-  EXPECT_EQ(2U, stack.Size());
-
-  stack.Push(3);
-  EXPECT_FALSE(stack.Empty());
-  EXPECT_EQ(3U, stack.Size());
-
-  stack.Remove(2);
-  EXPECT_FALSE(stack.Empty());
-  EXPECT_EQ(2U, stack.Size());
-
-  EXPECT_EQ(3, stack.Pop());
-  EXPECT_FALSE(stack.Empty());
-  EXPECT_EQ(1U, stack.Size());
-
-  EXPECT_EQ(1, stack.Pop());
-  EXPECT_TRUE(stack.Empty());
-  EXPECT_EQ(0U, stack.Size());
-}
-
-// Verify that a value can be pushed again after it has been removed.
-TEST(TaskSchedulerUniqueStackTest, PushAfterRemove) {
-  SchedulerUniqueStack<int> stack;
-  EXPECT_EQ(0U, stack.Size());
-  EXPECT_TRUE(stack.Empty());
-
-  stack.Push(5);
-  EXPECT_EQ(1U, stack.Size());
-  EXPECT_FALSE(stack.Empty());
-
-  stack.Remove(5);
-  EXPECT_EQ(0U, stack.Size());
-  EXPECT_TRUE(stack.Empty());
-
-  stack.Push(5);
-  EXPECT_EQ(1U, stack.Size());
-  EXPECT_FALSE(stack.Empty());
-}
-
-// Verify that Push() DCHECKs when a value is inserted twice.
-TEST(TaskSchedulerUniqueStackTest, PushTwice) {
-  SchedulerUniqueStack<int> stack;
-  stack.Push(5);
-  EXPECT_DCHECK_DEATH({ stack.Push(5); }, "");
-}
-
-}  // namespace internal
-}  // namespace base