[ash-md] Added a delay between system menu default/detailed view transitions.

base/test/scoped_mock_time_message_loop_task_runner_unittest.cc

+// Copyright 2015 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/test/scoped_mock_time_message_loop_task_runner.h"
+
+#include <deque>
+#include <memory>
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/callback_forward.h"
+#include "base/macros.h"
+#include "base/memory/ptr_util.h"
+#include "base/memory/ref_counted.h"
+#include "base/message_loop/message_loop.h"
+#include "base/test/test_mock_time_task_runner.h"
+#include "base/test/test_pending_task.h"
+#include "base/time/time.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+namespace {
+
+TaskRunner* GetCurrentTaskRunner() {
+  return MessageLoop::current()->task_runner().get();
+}
+
+// Pops a task from the front of |pending_tasks| and returns it.
+TestPendingTask PopFront(std::deque<TestPendingTask>* pending_tasks) {
+  TestPendingTask task = pending_tasks->front();
+  pending_tasks->pop_front();
+  return task;
+}
+
+class ScopedMockTimeMessageLoopTaskRunnerTest : public testing::Test {
+ public:
+  ScopedMockTimeMessageLoopTaskRunnerTest()
+      : original_task_runner_(new TestMockTimeTaskRunner()) {
+    MessageLoop::current()->SetTaskRunner(original_task_runner_);
+  }
+
+ protected:
+  TestMockTimeTaskRunner* original_task_runner() {
+    return original_task_runner_.get();
+  }
+
+ private:
+  scoped_refptr<TestMockTimeTaskRunner> original_task_runner_;
+
+  MessageLoop message_loop_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedMockTimeMessageLoopTaskRunnerTest);
+};
+
+// Verifies a new TaskRunner is installed while a
+// ScopedMockTimeMessageLoopTaskRunner exists and the previous one is installed
+// after destruction.
+TEST_F(ScopedMockTimeMessageLoopTaskRunnerTest, CurrentTaskRunners) {
+  auto scoped_task_runner_ =
+      base::MakeUnique<ScopedMockTimeMessageLoopTaskRunner>();
+  EXPECT_EQ(scoped_task_runner_->task_runner(), GetCurrentTaskRunner());
+  scoped_task_runner_.reset();
+  EXPECT_EQ(original_task_runner(), GetCurrentTaskRunner());
+}
+
+TEST_F(ScopedMockTimeMessageLoopTaskRunnerTest,
+       IncompleteTasksAreCopiedToPreviousTaskRunnerAfterDestruction) {
+  auto scoped_task_runner_ =
+      base::MakeUnique<ScopedMockTimeMessageLoopTaskRunner>();
+
+  Closure task_1 = Bind(&DoNothing);
+  Closure task_2 = Bind(&DoNothing);
+  Closure task_10 = Bind(&DoNothing);
+  Closure task_11 = Bind(&DoNothing);
+
+  constexpr TimeDelta task_1_delay = TimeDelta::FromSeconds(1);
+  constexpr TimeDelta task_2_delay = TimeDelta::FromSeconds(2);
+  constexpr TimeDelta task_10_delay = TimeDelta::FromSeconds(10);
+  constexpr TimeDelta task_11_delay = TimeDelta::FromSeconds(11);
+
+  constexpr TimeDelta step_time_by = TimeDelta::FromSeconds(5);
+
+  GetCurrentTaskRunner()->PostDelayedTask(FROM_HERE, task_1, task_1_delay);
+  GetCurrentTaskRunner()->PostDelayedTask(FROM_HERE, task_2, task_2_delay);
+  GetCurrentTaskRunner()->PostDelayedTask(FROM_HERE, task_10, task_10_delay);
+  GetCurrentTaskRunner()->PostDelayedTask(FROM_HERE, task_11, task_11_delay);
+
+  scoped_task_runner_->task_runner()->FastForwardBy(step_time_by);
+
+  scoped_task_runner_.reset();
+
+  std::deque<TestPendingTask> pending_tasks =
+      original_task_runner()->TakePendingTasks();
+
+  EXPECT_EQ(2U, pending_tasks.size());
+
+  TestPendingTask pending_task = PopFront(&pending_tasks);
+  EXPECT_TRUE(task_10.Equals(pending_task.task));
+  EXPECT_EQ(task_10_delay - step_time_by, pending_task.delay);
+
+  pending_task = PopFront(&pending_tasks);
+  EXPECT_TRUE(task_11.Equals(pending_task.task));
+  EXPECT_EQ(task_11_delay - step_time_by, pending_task.delay);
+}
+
+}  // namespace
+}  // namespace base