Implements the dialog view for logout confirmation dialog in public sessions.

Implements ash::internal::LogoutConfirmationDialogView which is supposed
to be used by ash::internal::LogoutButtonTray.

BUG=223846
TEST=new unit test

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=242286

Review URL: https://codereview.chromium.org/40053002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243530 0039d316-1c4b-4281-b951-d872f2087c98

ash/ash.gyp

@@ -332,6 +332,8 @@
         'system/logout_button/logout_button_observer.h',
         'system/logout_button/logout_button_tray.cc',
         'system/logout_button/logout_button_tray.h',
+        'system/logout_button/logout_confirmation_dialog_view.cc',
+        'system/logout_button/logout_confirmation_dialog_view.h',
         'system/monitor/tray_monitor.cc',
         'system/monitor/tray_monitor.h',
         'system/session_length_limit/session_length_limit_observer.h',
@@ -828,6 +830,7 @@
         'system/chromeos/screen_security/screen_tray_item_unittest.cc',
         'system/chromeos/tray_display_unittest.cc',
         'system/date/date_view_unittest.cc',
+        'system/logout_button/logout_button_tray_unittest.cc',
         'system/session_length_limit/tray_session_length_limit_unittest.cc',
         'system/tray/system_tray_unittest.cc',
         'system/tray/tray_details_view_unittest.cc',

ash/ash_strings.grd

@@ -585,6 +585,19 @@ Press Shift + Alt to switch.
         Press Control Shift Q twice to quit.
       </message>
 
+      <message name="IDS_ASH_LOGOUT_CONFIRMATION_TITLE" desc="Dialog title for the logout confirmation dialog.">
+        Exiting Session
+      </message>
+      <message name="IDS_ASH_LOGOUT_CONFIRMATION_WARNING" desc="The text for the logout confirmation dialog.">
+        You will automatically be signed out in <ph name="LOGOUT_TIME_LEFT">$1<ex>5 seconds</ex></ph>.
+      </message>
+      <message name="IDS_ASH_LOGOUT_CONFIRMATION_WARNING_NOW" desc="The text for the logout confirmation dialog with no time left.">
+        You will be signed out now.
+      </message>
+      <message name="IDS_ASH_LOGOUT_CONFIRMATION_BUTTON" desc="The text for okay button of the logout confirmation dialog.">
+        Sign out now
+      </message>
+
       <!-- ChromeOS-specific strings -->
       <if expr="pp_ifdef('chromeos')">
         <part file="ash_chromeos_strings.grdp" />

ash/system/logout_button/logout_button_observer.h

@@ -5,16 +5,24 @@
 #ifndef ASH_SYSTEM_LOGOUT_BUTTON_LOGOUT_BUTTON_OBSERVER_H_
 #define ASH_SYSTEM_LOGOUT_BUTTON_LOGOUT_BUTTON_OBSERVER_H_
 
+#include "ash/ash_export.h"
+#include "base/time/time.h"
+
 namespace ash {
 
-// Observer for the value of the kShowLogoutButtonInTray pref that determines
-// whether a logout button should be shown in the system tray during a session.
-class LogoutButtonObserver {
+class ASH_EXPORT LogoutButtonObserver {
  public:
   virtual ~LogoutButtonObserver() {}
 
-  // Called when the value of the kShowLogoutButtonInTray pref changes.
+  // Called when the value of the kShowLogoutButtonInTray pref changes, which
+  // determines whether a logout button should be shown in the system tray
+  // during a session.
   virtual void OnShowLogoutButtonInTrayChanged(bool show) = 0;
+
+  // Called when the value of the kLogoutDialogDurationMs pref changes.
+  // |duration| is the duration for which the logout confirmation dialog is
+  // shown after the user has pressed the logout button.
+  virtual void OnLogoutDialogDurationChanged(base::TimeDelta duration) = 0;
 };
 
 }  // namespace ash

ash/system/logout_button/logout_button_tray.cc

@@ -24,7 +24,6 @@
 #include "ui/views/painter.h"
 
 namespace ash {
-
 namespace internal {
 
 namespace {
@@ -64,6 +63,21 @@ class LogoutButton : public views::LabelButton {
   DISALLOW_COPY_AND_ASSIGN(LogoutButton);
 };
 
+class LogoutConfirmationDialogDelegate
+    : public LogoutConfirmationDialogView::Delegate {
+
+ public:
+  LogoutConfirmationDialogDelegate() {}
+  virtual ~LogoutConfirmationDialogDelegate() {}
+
+  virtual void LogoutCurrentUser() OVERRIDE;
+  virtual base::TimeTicks GetCurrentTime() const OVERRIDE;
+  virtual void ShowDialog(views::DialogDelegate* dialog) OVERRIDE;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(LogoutConfirmationDialogDelegate);
+};
+
 }  // namespace
 
 LogoutButton::LogoutButton(views::ButtonListener* listener)
@@ -95,20 +109,62 @@ LogoutButton::LogoutButton(views::ButtonListener* listener)
 LogoutButton::~LogoutButton() {
 }
 
+void LogoutConfirmationDialogDelegate::LogoutCurrentUser() {
+  Shell::GetInstance()->system_tray_delegate()->SignOut();
+}
+
+base::TimeTicks LogoutConfirmationDialogDelegate::GetCurrentTime() const {
+  return base::TimeTicks::Now();
+}
+
+void LogoutConfirmationDialogDelegate::ShowDialog(
+    views::DialogDelegate *dialog) {
+  views::DialogDelegate::CreateDialogWidget(
+      dialog, ash::Shell::GetPrimaryRootWindow(), NULL);
+  dialog->GetWidget()->Show();
+}
+
 LogoutButtonTray::LogoutButtonTray(StatusAreaWidget* status_area_widget)
     : TrayBackgroundView(status_area_widget),
       button_(NULL),
       login_status_(user::LOGGED_IN_NONE),
-      show_logout_button_in_tray_(false) {
+      show_logout_button_in_tray_(false),
+      confirmation_dialog_(NULL),
+      confirmation_delegate_(new LogoutConfirmationDialogDelegate) {
   button_ = new LogoutButton(this);
   tray_container()->AddChildView(button_);
   tray_container()->set_border(NULL);
-  Shell::GetInstance()->system_tray_notifier()->AddLogoutButtonObserver(this);
+  // The Shell may not exist in some unit tests.
+  if (Shell::HasInstance()) {
+    Shell::GetInstance()->system_tray_notifier()->
+        AddLogoutButtonObserver(this);
+  }
 }
 
 LogoutButtonTray::~LogoutButtonTray() {
-  Shell::GetInstance()->system_tray_notifier()->
-      RemoveLogoutButtonObserver(this);
+  EnsureConfirmationDialogIsClosed();
+  // The Shell may not exist in some unit tests.
+  if (Shell::HasInstance()) {
+    Shell::GetInstance()->system_tray_notifier()->
+        RemoveLogoutButtonObserver(this);
+  }
+}
+
+bool LogoutButtonTray::IsConfirmationDialogShowing() const {
+  return confirmation_dialog_ != NULL;
+}
+
+void LogoutButtonTray::EnsureConfirmationDialogIsShowing() {
+  if (!confirmation_dialog_) {
+    confirmation_dialog_ = new LogoutConfirmationDialogView(
+        this, confirmation_delegate_.get());
+    confirmation_dialog_->Show(dialog_duration_);
+  }
+}
+
+void LogoutButtonTray::EnsureConfirmationDialogIsClosed() {
+  if (confirmation_dialog_)
+    confirmation_dialog_->Close();
 }
 
 void LogoutButtonTray::SetShelfAlignment(ShelfAlignment alignment) {
@@ -133,10 +189,20 @@ void LogoutButtonTray::OnShowLogoutButtonInTrayChanged(bool show) {
   UpdateVisibility();
 }
 
+void LogoutButtonTray::OnLogoutDialogDurationChanged(base::TimeDelta duration) {
+  dialog_duration_ = duration;
+  if (confirmation_dialog_)
+    confirmation_dialog_->UpdateDialogDuration(dialog_duration_);
+}
+
 void LogoutButtonTray::ButtonPressed(views::Button* sender,
                                      const ui::Event& event) {
   DCHECK_EQ(sender, button_);
-  Shell::GetInstance()->system_tray_delegate()->SignOut();
+  // Sign out immediately if |dialog_duration_| is non-positive.
+  if (dialog_duration_ <= base::TimeDelta())
+    confirmation_delegate_->LogoutCurrentUser();
+  else
+    EnsureConfirmationDialogIsShowing();
 }
 
 void LogoutButtonTray::UpdateAfterLoginStatusChange(
@@ -149,10 +215,21 @@ void LogoutButtonTray::UpdateAfterLoginStatusChange(
   UpdateVisibility();
 }
 
+void LogoutButtonTray::ReleaseConfirmationDialog() {
+  confirmation_dialog_ = NULL;
+}
+
+void LogoutButtonTray::SetDelegateForTest(
+    scoped_ptr<LogoutConfirmationDialogView::Delegate> delegate) {
+  confirmation_delegate_ = delegate.Pass();
+}
+
 void LogoutButtonTray::UpdateVisibility() {
   SetVisible(show_logout_button_in_tray_ &&
              login_status_ != user::LOGGED_IN_NONE &&
              login_status_ != user::LOGGED_IN_LOCKED);
+  if (!show_logout_button_in_tray_)
+    EnsureConfirmationDialogIsClosed();
 }
 
 }  // namespace internal

ash/system/logout_button/logout_button_tray.h

@@ -5,11 +5,15 @@
 #ifndef ASH_SYSTEM_LOGOUT_BUTTON_LOGOUT_BUTTON_TRAY_H_
 #define ASH_SYSTEM_LOGOUT_BUTTON_LOGOUT_BUTTON_TRAY_H_
 
+#include "ash/ash_export.h"
 #include "ash/system/logout_button/logout_button_observer.h"
+#include "ash/system/logout_button/logout_confirmation_dialog_view.h"
 #include "ash/system/tray/tray_background_view.h"
 #include "ash/system/user/login_status.h"
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/time/time.h"
 #include "ui/views/controls/button/button.h"
 
 namespace views {
@@ -23,9 +27,9 @@ class StatusAreaWidget;
 
 // Adds a logout button to the launcher's status area if enabled by the
 // kShowLogoutButtonInTray pref.
-class LogoutButtonTray : public TrayBackgroundView,
-                         public LogoutButtonObserver,
-                         public views::ButtonListener {
+class ASH_EXPORT LogoutButtonTray : public TrayBackgroundView,
+                                    public LogoutButtonObserver,
+                                    public views::ButtonListener {
  public:
   explicit LogoutButtonTray(StatusAreaWidget* status_area_widget);
   virtual ~LogoutButtonTray();
@@ -39,6 +43,7 @@ class LogoutButtonTray : public TrayBackgroundView,
 
   // LogoutButtonObserver:
   virtual void OnShowLogoutButtonInTrayChanged(bool show) OVERRIDE;
+  virtual void OnLogoutDialogDurationChanged(base::TimeDelta duration) OVERRIDE;
 
   // views::ButtonListener:
   virtual void ButtonPressed(views::Button* sender,
@@ -46,12 +51,30 @@ class LogoutButtonTray : public TrayBackgroundView,
 
   void UpdateAfterLoginStatusChange(user::LoginStatus login_status);
 
+  // Nullify the pointer to confirmation dialog, this is expected to be called
+  // when the confirmation dialog is going to be destroyed.
+  // Note: the confirmation dialog is not owned by LogoutButtonTray.
+  void ReleaseConfirmationDialog();
+
+  void SetDelegateForTest(
+      scoped_ptr<LogoutConfirmationDialogView::Delegate> delegate);
+
  private:
+  friend class LogoutConfirmationDialogTest;
+
+  bool IsConfirmationDialogShowing() const;
+  void EnsureConfirmationDialogIsShowing();
+  void EnsureConfirmationDialogIsClosed();
+
   void UpdateVisibility();
 
   views::LabelButton* button_;  // Not owned.
   user::LoginStatus login_status_;
   bool show_logout_button_in_tray_;
+  base::TimeDelta dialog_duration_;
+
+  LogoutConfirmationDialogView* confirmation_dialog_;  // Not owned.
+  scoped_ptr<LogoutConfirmationDialogView::Delegate> confirmation_delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(LogoutButtonTray);
 };

ash/system/logout_button/logout_confirmation_dialog_view.cc

+// Copyright 2014 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 "ash/system/logout_button/logout_confirmation_dialog_view.h"
+
+#include "ash/shell.h"
+#include "ash/system/logout_button/logout_button_tray.h"
+#include "ash/system/tray/system_tray_delegate.h"
+#include "ash/system/tray/tray_constants.h"
+#include "base/location.h"
+#include "grit/ash_strings.h"
+#include "ui/aura/root_window.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/base/l10n/time_format.h"
+#include "ui/base/ui_base_types.h"
+#include "ui/gfx/text_constants.h"
+#include "ui/views/border.h"
+#include "ui/views/controls/label.h"
+#include "ui/views/layout/fill_layout.h"
+#include "ui/views/widget/widget.h"
+
+namespace ash {
+namespace internal {
+
+namespace {
+
+const int kCountdownUpdateIntervalMs = 1000;  // 1 second.
+
+inline int Round(double x) {
+    return static_cast<int>(x + 0.5);
+}
+
+}  // namespace
+
+LogoutConfirmationDialogView::LogoutConfirmationDialogView(
+    LogoutButtonTray* owner, Delegate* delegate) : owner_(owner),
+                                                   delegate_(delegate) {
+  text_label_ = new views::Label;
+  text_label_->set_border(
+      views::Border::CreateEmptyBorder(0, kTrayPopupPaddingHorizontal,
+                                       0, kTrayPopupPaddingHorizontal));
+  text_label_->SetHorizontalAlignment(gfx::ALIGN_LEFT);
+  text_label_->SetMultiLine(true);
+
+  SetLayoutManager(new views::FillLayout());
+
+  AddChildView(text_label_);
+}
+
+LogoutConfirmationDialogView::~LogoutConfirmationDialogView() {
+}
+
+bool LogoutConfirmationDialogView::Accept() {
+  LogoutCurrentUser();
+  return true;
+}
+
+ui::ModalType LogoutConfirmationDialogView::GetModalType() const {
+  return ui::MODAL_TYPE_SYSTEM;
+}
+
+base::string16 LogoutConfirmationDialogView::GetWindowTitle() const {
+  return l10n_util::GetStringUTF16(IDS_ASH_LOGOUT_CONFIRMATION_TITLE);
+}
+
+base::string16 LogoutConfirmationDialogView::GetDialogButtonLabel(
+    ui::DialogButton button) const {
+  if (button == ui::DIALOG_BUTTON_OK)
+    return l10n_util::GetStringUTF16(IDS_ASH_LOGOUT_CONFIRMATION_BUTTON);
+  return views::DialogDelegateView::GetDialogButtonLabel(button);
+}
+
+void LogoutConfirmationDialogView::OnClosed() {
+  owner_->ReleaseConfirmationDialog();
+  owner_ = NULL;
+  timer_.Stop();
+  // Nullify the delegate to prevent future activities of the dialog.
+  delegate_ = NULL;
+}
+
+void LogoutConfirmationDialogView::DeleteDelegate() {
+  if (owner_)
+    owner_->ReleaseConfirmationDialog();
+  delete this;
+}
+
+void LogoutConfirmationDialogView::Show(base::TimeDelta duration) {
+  if (!delegate_)
+    return;
+  countdown_start_time_ = delegate_->GetCurrentTime();
+  duration_ = duration;
+
+  UpdateCountdown();
+
+  delegate_->ShowDialog(this);
+
+  timer_.Start(FROM_HERE,
+               base::TimeDelta::FromMilliseconds(kCountdownUpdateIntervalMs),
+               this,
+               &LogoutConfirmationDialogView::UpdateCountdown);
+}
+
+void LogoutConfirmationDialogView::UpdateDialogDuration(
+    base::TimeDelta duration) {
+  duration_ = duration;
+  UpdateCountdown();
+}
+
+void LogoutConfirmationDialogView::LogoutCurrentUser() {
+  if (!delegate_)
+    return;
+  delegate_->LogoutCurrentUser();
+}
+
+void LogoutConfirmationDialogView::UpdateCountdown() {
+  if (!delegate_)
+    return;
+  const base::TimeDelta time_remaining = countdown_start_time_ +
+      duration_ - delegate_->GetCurrentTime();
+  // Round the remaining time to nearest second, and use this value for
+  // the countdown display and actual enforcement.
+  int seconds_remaining = Round(time_remaining.InSecondsF());
+  if (seconds_remaining > 0) {
+    text_label_->SetText(l10n_util::GetStringFUTF16(
+        IDS_ASH_LOGOUT_CONFIRMATION_WARNING,
+        ui::TimeFormat::TimeDurationLong(base::TimeDelta::FromSeconds(
+            seconds_remaining))));
+  } else {
+    text_label_->SetText(l10n_util::GetStringUTF16(
+        IDS_ASH_LOGOUT_CONFIRMATION_WARNING_NOW));
+    timer_.Stop();
+    LogoutCurrentUser();
+  }
+}
+
+}  // namespace internal
+}  // namespace ash

ash/system/logout_button/logout_confirmation_dialog_view.h

+// Copyright 2014 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 ASH_SYSTEM_LOGOUT_BUTTON_LOGOUT_CONFIRMATION_DIALOG_VIEW_H_
+#define ASH_SYSTEM_LOGOUT_BUTTON_LOGOUT_CONFIRMATION_DIALOG_VIEW_H_
+
+#include "ash/ash_export.h"
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/time/time.h"
+#include "base/timer/timer.h"
+#include "ui/views/window/dialog_delegate.h"
+
+namespace views {
+class Label;
+}
+
+namespace ash {
+namespace internal {
+
+class LogoutButtonTray;
+
+// This class implements dialog view for logout confirmation.
+class ASH_EXPORT LogoutConfirmationDialogView
+    : public views::DialogDelegateView {
+ public:
+  class ASH_EXPORT Delegate {
+   public:
+    virtual ~Delegate() {}
+
+    virtual void LogoutCurrentUser() = 0;
+    virtual base::TimeTicks GetCurrentTime() const = 0;
+    virtual void ShowDialog(views::DialogDelegate* dialog) = 0;
+  };
+
+  LogoutConfirmationDialogView(LogoutButtonTray* owner, Delegate* delegate);
+  virtual ~LogoutConfirmationDialogView();
+
+  // views::DialogDelegateView:
+  virtual bool Accept() OVERRIDE;
+  virtual ui::ModalType GetModalType() const OVERRIDE;
+  virtual base::string16 GetWindowTitle() const OVERRIDE;
+  virtual base::string16
+      GetDialogButtonLabel(ui::DialogButton button) const OVERRIDE;
+  virtual void OnClosed() OVERRIDE;
+  virtual void DeleteDelegate() OVERRIDE;
+
+  void Show(base::TimeDelta duration);
+
+  // The duration of the confirmation dialog can be changed while the dialog
+  // is still showing. This method is only expected to be called when the
+  // preference for confirmation dialog duration has changed.
+  void UpdateDialogDuration(base::TimeDelta duration);
+
+ private:
+  void LogoutCurrentUser();
+  void UpdateCountdown();
+
+  views::Label* text_label_;
+
+  base::TimeTicks countdown_start_time_;
+  base::TimeDelta duration_;
+
+  base::RepeatingTimer<LogoutConfirmationDialogView> timer_;
+
+  LogoutButtonTray* owner_;
+
+  Delegate* delegate_;
+
+  DISALLOW_COPY_AND_ASSIGN(LogoutConfirmationDialogView);
+};
+
+}  // namespace internal
+}  // namespace ash
+
+#endif  // ASH_SYSTEM_LOGOUT_BUTTON_LOGOUT_CONFIRMATION_DIALOG_VIEW_H_

ash/system/tray/system_tray_notifier.cc

@@ -232,6 +232,13 @@ void SystemTrayNotifier::NotifyShowLoginButtonChanged(bool show_login_button) {
                     OnShowLogoutButtonInTrayChanged(show_login_button));
 }
 
+void SystemTrayNotifier::NotifyLogoutDialogDurationChanged(
+    base::TimeDelta duration) {
+  FOR_EACH_OBSERVER(LogoutButtonObserver,
+                    logout_button_observers_,
+                    OnLogoutDialogDurationChanged(duration));
+}
+
 void SystemTrayNotifier::NotifyLocaleChanged(
     LocaleObserver::Delegate* delegate,
     const std::string& cur_locale,

ash/system/tray/system_tray_notifier.h

@@ -22,6 +22,7 @@
 #include "ash/system/user/update_observer.h"
 #include "ash/system/user/user_observer.h"
 #include "base/observer_list.h"
+#include "base/time/time.h"
 
 #if defined(OS_CHROMEOS)
 #include "ash/system/chromeos/enterprise/enterprise_domain_observer.h"
@@ -103,6 +104,7 @@ public:
   void NotifyDriveJobUpdated(const DriveOperationStatus& status);
   void NotifyRefreshIME(bool show_message);
   void NotifyShowLoginButtonChanged(bool show_login_button);
+  void NotifyLogoutDialogDurationChanged(base::TimeDelta duration);
   void NotifyLocaleChanged(LocaleObserver::Delegate* delegate,
                            const std::string& cur_locale,
                            const std::string& from_locale,

chrome/browser/ui/ash/chrome_launcher_prefs.cc

@@ -68,13 +68,17 @@ void RegisterChromeLauncherUserPrefs(
       prefs::kShelfAlignmentLocal,
       std::string(),
       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDictionaryPref(
+      prefs::kShelfPreferences,
+      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterIntegerPref(
+      prefs::kLogoutDialogDurationMs,
+      20000,
+      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
   registry->RegisterBooleanPref(
       prefs::kShowLogoutButtonInTray,
       false,
       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
-  registry->RegisterDictionaryPref(
-      prefs::kShelfPreferences,
-      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 }
 
 base::DictionaryValue* CreateAppDict(const std::string& app_id) {

chrome/browser/ui/ash/system_tray_delegate_chromeos.cc

@@ -908,6 +908,10 @@ class SystemTrayDelegate : public ash::SystemTrayDelegate,
         prefs::kShowLogoutButtonInTray,
         base::Bind(&SystemTrayDelegate::UpdateShowLogoutButtonInTray,
                    base::Unretained(this)));
+    user_pref_registrar_->Add(
+        prefs::kLogoutDialogDurationMs,
+        base::Bind(&SystemTrayDelegate::UpdateLogoutDialogDuration,
+                   base::Unretained(this)));
     user_pref_registrar_->Add(
         prefs::kLargeCursorEnabled,
         base::Bind(&SystemTrayDelegate::OnAccessibilityModeChanged,
@@ -930,6 +934,7 @@ class SystemTrayDelegate : public ash::SystemTrayDelegate,
 
     UpdateClockType();
     UpdateShowLogoutButtonInTray();
+    UpdateLogoutDialogDuration();
     UpdatePerformanceTracing();
     search_key_mapped_to_ =
         profile->GetPrefs()->GetInteger(prefs::kLanguageRemapSearchKeyTo);
@@ -1001,6 +1006,13 @@ class SystemTrayDelegate : public ash::SystemTrayDelegate,
             prefs::kShowLogoutButtonInTray));
   }
 
+  void UpdateLogoutDialogDuration() {
+    const int duration_ms = user_pref_registrar_->prefs()->GetInteger(
+        prefs::kLogoutDialogDurationMs);
+    GetSystemTrayNotifier()->NotifyLogoutDialogDurationChanged(
+        base::TimeDelta::FromMilliseconds(duration_ms));
+  }
+
   void UpdateSessionStartTime() {
     const PrefService* local_state = local_state_registrar_->prefs();
     if (local_state->HasPrefPath(prefs::kSessionStartTime)) {

chrome/common/pref_names.cc

@@ -2464,15 +2464,20 @@ const char kShelfAutoHideBehaviorLocal[] = "auto_hide_behavior_local";
 // index is also stored in the |kPinnedLauncherApp| pref. It may causes
 // creating two chrome icons.
 const char kShelfChromeIconIndex[] = "shelf_chrome_icon_index";
-
-const char kPinnedLauncherApps[] = "pinned_launcher_apps";
-// Boolean value indicating whether to show a logout button in the ash tray.
-const char kShowLogoutButtonInTray[] = "show_logout_button_in_tray";
 // Dictionary value that holds per-display preference of shelf alignment and
 // auto-hide behavior. Key of the dictionary is the id of the display, and
 // its value is a dictionary whose keys are kShelfAlignment and
 // kShelfAutoHideBehavior.
 const char kShelfPreferences[] = "shelf_preferences";
+
+// Integer value in milliseconds indicating the length of time for which a
+// confirmation dialog should be shown when the user presses the logout button.
+// A value of 0 indicates that logout should happen immediately, without showing
+// a confirmation dialog.
+const char kLogoutDialogDurationMs[] = "logout_dialog_duration_ms";
+const char kPinnedLauncherApps[] = "pinned_launcher_apps";
+// Boolean value indicating whether to show a logout button in the ash tray.
+const char kShowLogoutButtonInTray[] = "show_logout_button_in_tray";
 #endif
 
 #if defined(USE_AURA)

chrome/common/pref_names.h

@@ -851,9 +851,11 @@ extern const char kShelfAlignmentLocal[];
 extern const char kShelfAutoHideBehavior[];
 extern const char kShelfAutoHideBehaviorLocal[];
 extern const char kShelfChromeIconIndex[];
+extern const char kShelfPreferences[];
+
+extern const char kLogoutDialogDurationMs[];
 extern const char kPinnedLauncherApps[];
 extern const char kShowLogoutButtonInTray[];
-extern const char kShelfPreferences[];
 #endif
 
 #if defined(USE_AURA)