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

base/test/scoped_mock_time_message_loop_task_runner.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 "base/logging.h"
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
+#include "base/test/test_pending_task.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "base/time/time.h"
+
+namespace base {
+
+ScopedMockTimeMessageLoopTaskRunner::ScopedMockTimeMessageLoopTaskRunner()
+    : task_runner_(new TestMockTimeTaskRunner),
+      previous_task_runner_(ThreadTaskRunnerHandle::Get()) {
+  DCHECK(MessageLoop::current());
+  // To ensure that we process any initialization tasks posted to the
+  // MessageLoop by a test fixture before replacing its TaskRunner.
+  RunLoop().RunUntilIdle();
+  MessageLoop::current()->SetTaskRunner(task_runner_);
+}
+
+ScopedMockTimeMessageLoopTaskRunner::~ScopedMockTimeMessageLoopTaskRunner() {
+  DCHECK(previous_task_runner_->RunsTasksOnCurrentThread());
+  DCHECK_EQ(task_runner_, ThreadTaskRunnerHandle::Get());
+  for (const auto& pending_task : task_runner_->TakePendingTasks()) {
+    previous_task_runner_->PostDelayedTask(
+        pending_task.location, pending_task.task,
+        pending_task.GetTimeToRun() - task_runner_->NowTicks());
+  }
+  MessageLoop::current()->SetTaskRunner(std::move(previous_task_runner_));
+}
+
+}  // namespace base