Add device policy to disallow shutdown - ash UI modifications

chrome/browser/ui/ash/system_tray_delegate_chromeos.cc

Index: chrome/browser/ui/ash/system_tray_delegate_chromeos.cc
diff --git a/chrome/browser/ui/ash/system_tray_delegate_chromeos.cc b/chrome/browser/ui/ash/system_tray_delegate_chromeos.cc
index 85c8e85c9310879986d18c25bfbfc1a7ea3bab0f..ecd38165cd2710a216237224d63140d448f731b3 100644
--- a/chrome/browser/ui/ash/system_tray_delegate_chromeos.cc
+++ b/chrome/browser/ui/ash/system_tray_delegate_chromeos.cc
@@ -19,6 +19,7 @@
 #include "ash/shell_window_ids.h"
 #include "ash/system/bluetooth/bluetooth_observer.h"
 #include "ash/system/chromeos/session/logout_button_observer.h"
+#include "ash/system/chromeos/shutdown_policy_observer.h"
 #include "ash/system/date/clock_observer.h"
 #include "ash/system/ime/ime_observer.h"
 #include "ash/system/tray/system_tray.h"
@@ -30,6 +31,7 @@
 #include "ash/system/user/user_observer.h"
 #include "ash/volume_control_delegate.h"
 #include "ash/wm/lock_state_controller.h"
+#include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/logging.h"
@@ -134,6 +136,12 @@ void ExtractIMEInfo(const input_method::InputMethodDescriptor& ime,
   info->third_party = extension_ime_util::IsExtensionIME(ime.id());
 }
 
+void TriggerShutdown(bool reboot_on_shutdown) {
+  ash::Shell::GetInstance()->lock_state_controller()->RequestShutdown(
+      reboot_on_shutdown ? ash::LockStateController::RESTART
+                         : ash::LockStateController::POWER_OFF);
+}
+
 gfx::NativeWindow GetNativeWindowByStatus(ash::user::LoginStatus login_status,
                                           bool session_started) {
   bool isUserAddingRunning = ash::Shell::GetInstance()
@@ -225,6 +233,8 @@ SystemTrayDelegateChromeOS::SystemTrayDelegateChromeOS()
                  base::Unretained(this)));
 
   user_manager::UserManager::Get()->AddSessionStateObserver(this);
+  shutdown_policy_observer_.reset(
+      new ShutdownPolicyObserver(CrosSettings::Get(), this));
 }
 
 void SystemTrayDelegateChromeOS::Initialize() {
@@ -591,9 +601,14 @@ void SystemTrayDelegateChromeOS::ShowUserLogin() {
   }
 }
 
-void SystemTrayDelegateChromeOS::ShutDown() {
+void SystemTrayDelegateChromeOS::Restart() {
   ash::Shell::GetInstance()->lock_state_controller()->RequestShutdown(
-      ash::LockStateController::POWER_OFF);
+      ash::LockStateController::RESTART);

[stevenjb, 2014/12/17 19:09:02]

It seems super silly for the ash system tray delegate to call back into
ash::Shell. Why not have the UI call ash::Shell directly? (I realize we are
already doing that with Shutdown(), but we should fix that too).

[cschuet (SLOW), 2015/01/07 14:37:07]

Done.

+}
+
+void SystemTrayDelegateChromeOS::ShutDown() {
+  shutdown_policy_observer_->CheckIfRebootOnShutdown(
+      base::Bind(&TriggerShutdown));

[stevenjb, 2014/12/17 19:09:02]

This has gotten a bit out of hand:
1. The UI asks this delegate to Shutdown.
2. This delegate calls ShutdownPolicy{Handler} to check policy.
3. This delegate then calls into ash::LockStateController to request either
Shutdown or Restart.
4. ash::LockStateController eventually calls
SessionStateControllerDelegateChromeos to request the actual shutdown or
restart.

Unless we have concrete plans allow a non-policy enforced 'Restart' in the UI, I
recommend doing the following instead:

* Remove both Restart() and ShutDown() from this delegate
* Call
ash::Shell::GetInstance()->lock_state_controller()->RequestShutdownOrRestart()
directly from the UI.
* Have SessionStateControllerDelegateChromeos check the policy and translate
Shutdown -> Restart

That way the UI is only using ShutdownPolicy{Handler} to inform what label to
show, and we don't rely on a delegate to do the policy checking.

WDYT?

[cschuet (SLOW), 2015/01/07 14:37:07]

Done.

 }
 
 void SystemTrayDelegateChromeOS::SignOut() {
@@ -834,6 +849,21 @@ void SystemTrayDelegateChromeOS::RemoveCustodianInfoTrayObserver(
   custodian_info_changed_observers_.RemoveObserver(observer);
 }
 
+void SystemTrayDelegateChromeOS::AddShutdownPolicyObserver(
+    ash::ShutdownPolicyObserver* observer) {
+  shutdown_policy_observers_.AddObserver(observer);
+}
+
+void SystemTrayDelegateChromeOS::ShouldRebootOnShutdown(
+    const ash::RebootOnShutdownCallback& callback) {
+  shutdown_policy_observer_->CheckIfRebootOnShutdown(callback);
+}
+
+void SystemTrayDelegateChromeOS::RemoveShutdownPolicyObserver(
+    ash::ShutdownPolicyObserver* observer) {
+  shutdown_policy_observers_.RemoveObserver(observer);
+}
+
 void SystemTrayDelegateChromeOS::UserAddedToSession(
     const user_manager::User* active_user) {
 }
@@ -1297,6 +1327,13 @@ void SystemTrayDelegateChromeOS::OnAccessibilityStatusChanged(
     OnAccessibilityModeChanged(details.notify);
 }
 
+void SystemTrayDelegateChromeOS::OnShutdownPolicyChanged(
+    bool reboot_on_shutdown) {
+  // Notify all observers.
+  FOR_EACH_OBSERVER(ash::ShutdownPolicyObserver, shutdown_policy_observers_,
+                    OnShutdownPolicyChanged(reboot_on_shutdown));
+}
+
 ash::SystemTrayDelegate* CreateSystemTrayDelegate() {
   return new SystemTrayDelegateChromeOS();
 }