Add device policy to disallow shutdown - ash UI modifications

ash/system/tray/system_tray_delegate.h

Index: ash/system/tray/system_tray_delegate.h
diff --git a/ash/system/tray/system_tray_delegate.h b/ash/system/tray/system_tray_delegate.h
index 228865b388c2757e1dab99596e0d8d72b241e164..eabb1257b2ce1542e81f54d407767d9422bc2cd7 100644
--- a/ash/system/tray/system_tray_delegate.h
+++ b/ash/system/tray/system_tray_delegate.h
@@ -25,6 +25,7 @@ class TimeTicks;
 namespace ash {
 
 class CustodianInfoTrayObserver;
+class ShutdownPolicyObserver;
 
 struct ASH_EXPORT NetworkIconInfo {
   NetworkIconInfo();
@@ -98,6 +99,8 @@ typedef std::vector<IMEInfo> IMEInfoList;
 
 class VolumeControlDelegate;
 
+using RebootOnShutdownCallback = base::Callback<void(bool)>;

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

Update other typedefs in this header to 'using'

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

Done.

+
 namespace tray {
 class UserAccountsDelegate;
 }  // namespace tray
@@ -199,6 +202,9 @@ class ASH_EXPORT SystemTrayDelegate {
   // Shows login UI to add other users to this session.
   virtual void ShowUserLogin() = 0;
 
+  // Attempts to reboot the system.

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

restart

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

This function has been removed in the new version of this CL.

+  virtual void Restart() = 0;
+
   // Attempts to shut down the system.
   virtual void ShutDown() = 0;
 
@@ -297,6 +303,21 @@ class ASH_EXPORT SystemTrayDelegate {
 
   virtual void RemoveCustodianInfoTrayObserver(
       CustodianInfoTrayObserver* observer) = 0;
+
+  // Adds an observer whose |OnShutdownPolicyChanged| function is called when
+  // the |DeviceRebootOnShutdown| policy changes. If this policy is set to
+  // true, a device cannot be shut down anymore but only rebooted.
+  virtual void AddShutdownPolicyObserver(ShutdownPolicyObserver* observer) = 0;
+
+  // Determines whether the device is automatically rebooted when shut down as
+  // specified by the device policy |DeviceRebootOnShutdown|. This function
+  // asynchronously calls |RebootOnShutdownCallback| once a trusted policy

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

Use variable name |callback| instead of type.

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

Done.

+  // becomes available.
+  virtual void ShouldRebootOnShutdown(
+      const RebootOnShutdownCallback& callback) = 0;

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

This should be named something like 'RequestShouldRebootOnShutdown', otherwise
it looks like a setter.

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

ShouldRebootOnShutdown is supposed to sound like a question "Should we reboot on
shutdown?". I think a setter would be called SetRebootOnShutdown. If you feel
strongly about this I will change it, but 'RequestShouldRebootOnShutdown' is a
bit clunky, I think.

+
+  virtual void RemoveShutdownPolicyObserver(

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

Remove should follow Add here and elsewhere.

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

Done.

+      ShutdownPolicyObserver* observer) = 0;
 };
 
 }  // namespace ash