Implements the dialog view for logout button tray in public sessions.

ash/system/logout_button/logout_button_tray.cc

Index: ash/system/logout_button/logout_button_tray.cc
diff --git a/ash/system/logout_button/logout_button_tray.cc b/ash/system/logout_button/logout_button_tray.cc
index c06073040c5c26822b641ecb479f29c65cae088f..08c3ea27fda0504da80e597fb568bdd0c411d7b7 100644
--- a/ash/system/logout_button/logout_button_tray.cc
+++ b/ash/system/logout_button/logout_button_tray.cc
@@ -6,8 +6,8 @@
 
 #include "ash/shelf/shelf_types.h"
 #include "ash/shell.h"
+#include "ash/system/logout_button/logout_confirmation_dialog_view.h"
 #include "ash/system/status_area_widget.h"
-#include "ash/system/tray/system_tray_delegate.h"
 #include "ash/system/tray/system_tray_notifier.h"
 #include "ash/system/tray/tray_constants.h"
 #include "ash/system/tray/tray_utils.h"
@@ -96,7 +96,6 @@ LogoutButton::~LogoutButton() {
 
 LogoutButtonTray::LogoutButtonTray(StatusAreaWidget* status_area_widget)
     : TrayBackgroundView(status_area_widget),
-      button_(NULL),
       login_status_(user::LOGGED_IN_NONE),
       show_logout_button_in_tray_(false) {
   button_ = new LogoutButton(this);
@@ -110,6 +109,19 @@ LogoutButtonTray::~LogoutButtonTray() {
       RemoveLogoutButtonObserver(this);
 }
 
+void LogoutButtonTray::EnsureConfirmationDialogShown() {
+  if (!confirm_dialog_) {
+    confirm_dialog_ = (new LogoutConfirmationDialogView())->GetWeakPtr();

[bartfab (slow), 2013/10/28 16:24:07]

The construction in this line is hard to follow.

Also, while WeakPtr works well here, I realize that it makes the ownership
relation very ambiguous. Sorry for the fore-and-back but I actually think it
would be best if LogoutButtonTray had a scoped_ptr that owns the
LogoutConfirmationDialogView. When the dialog closes, it notifies the button
which clears the scoped_ptr, as you had originally implemented it.

+    confirm_dialog_->Show(dialog_duration_);
+  }
+}
+
+void LogoutButtonTray::EnsureConfirmationDialogClosed() {
+  if (!confirm_dialog_) {

[bartfab (slow), 2013/10/28 16:24:07]

You want the exact reverse: if (confirm_dialog_)

Also, nit: No braces for single-line conditionals.

[binjin, 2013/10/29 16:07:05]

Done.

+    confirm_dialog_->GetWidget()->Close();
+  }
+}
+
 void LogoutButtonTray::SetShelfAlignment(ShelfAlignment alignment) {
   TrayBackgroundView::SetShelfAlignment(alignment);
   tray_container()->set_border(NULL);
@@ -132,10 +144,18 @@ void LogoutButtonTray::OnShowLogoutButtonInTrayChanged(bool show) {
   UpdateVisibility();
 }
 
+void LogoutButtonTray::OnLogoutDialogDurationChanged(int duration) {
+  dialog_duration_ = base::TimeDelta::FromMilliseconds(duration);

[bartfab (slow), 2013/10/28 16:24:07]

You need to update the dialog here. It should immediately reflect the updated
duration.

[binjin, 2013/10/29 16:07:05]

Done.

+}
+
 void LogoutButtonTray::ButtonPressed(views::Button* sender,
                                      const ui::Event& event) {
   DCHECK_EQ(sender, button_);
-  Shell::GetInstance()->system_tray_delegate()->SignOut();
+  if (dialog_duration_.InSeconds() <= 0) {

[bartfab (slow), 2013/10/28 16:24:07]

The correct way to do this would be something like:

if (dialog_duration < base::TimeDelta::FromSeconds(0))

Also, nit 1: No braces for single-line conditionals.

Also, nit 2: Add a comment that explains what is happening here.

[binjin, 2013/10/29 16:07:05]

Done.

+    Shell::GetInstance()->system_tray_delegate()->SignOut();
+  } else {
+    EnsureConfirmationDialogShown();
+  }
 }
 
 void LogoutButtonTray::UpdateAfterLoginStatusChange(
@@ -152,6 +172,8 @@ 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_)
+    EnsureConfirmationDialogClosed();
 }
 
 }  // namespace internal