Add the ability to show a demo app on OOBE if a machine is derelict.

chrome/browser/chromeos/idle_detector.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 "chrome/browser/chromeos/idle_detector.h"
+
+#include "ash/shell.h"
+#include "ash/wm/user_activity_detector.h"
+#include "base/bind.h"
+#include "base/lazy_instance.h"
+#include "base/logging.h"
+#include "base/message_loop/message_loop.h"
+
+namespace chromeos {
+
+IdleDetector::IdleDetector(const base::Closure& on_active_callback,
+                           const base::Closure& on_idle_callback)
+    : active_callback_(on_active_callback), idle_callback_(on_idle_callback) {}
+
+IdleDetector::~IdleDetector() {
+  if (ash::Shell::HasInstance() &&
+      ash::Shell::GetInstance()->user_activity_detector()->HasObserver(this))
+    ash::Shell::GetInstance()->user_activity_detector()->RemoveObserver(this);
+}
+
+void IdleDetector::OnUserActivity(const ui::Event* event) {
+  active_callback_.Run();

[xiyuan, 2014/02/11 03:42:45]

OnUserActivity is called quite frequently and we should avoid unnecessary calls.

Can we support null callback and skip call if callback.is_null()?

[rkc, 2014/02/11 04:35:57]

Done.

+  ResetTimer();
+}
+
+void IdleDetector::Start(const base::TimeDelta& timeout) {
+  timeout_ = timeout;
+  if (!ash::Shell::GetInstance()->user_activity_detector()->HasObserver(this))
+    ash::Shell::GetInstance()->user_activity_detector()->AddObserver(this);
+  ResetTimer();
+}
+
+void IdleDetector::ResetTimer() {
+  if (timer_.IsRunning()) {
+    timer_.Reset();
+  } else {
+    timer_.Start(FROM_HERE, timeout_, idle_callback_);
+  }
+}
+
+}  // namespace chromeos