Add dark resume methods to PowerManagerClient

chromeos/dbus/power_manager_client.h

Index: chromeos/dbus/power_manager_client.h
diff --git a/chromeos/dbus/power_manager_client.h b/chromeos/dbus/power_manager_client.h
index f37476e0127202e90ccfdb35c93a9f45ba0984b1..e9e1d00f105c44dde2e11f7960b0b03fc319bad7 100644
--- a/chromeos/dbus/power_manager_client.h
+++ b/chromeos/dbus/power_manager_client.h
@@ -71,6 +71,14 @@ class CHROMEOS_EXPORT PowerManagerClient : public DBusClient {
     // suspended (if e.g. the user canceled the suspend attempt).
     virtual void SuspendDone(const base::TimeDelta& sleep_duration) {}
 
+    // Called when the system is about to resuspend from a dark resume.  Like
+    // SuspendImminent(), the suspend will be deferred until all observers have
+    // finished running and those observers that wish to asynchromously delay

[Daniel Erat, 2014/08/15 23:49:31]

nit: s/asynchromously/asynchronously/

+    // the suspend should call PowerManagerClient::GetSuspendReadinessCallback()

[Daniel Erat, 2014/08/15 23:49:31]

sharing GetSuspendReadinessCallback() for this probably isn't the right
approach; i'm concerned that some observers that are just interested in normal
suspends will fail to call this before dark suspends. adding a new
GetDarkSuspendReadinessCallback() method is probably the best approach.

[Chirantan Ekbote, 2014/08/18 17:49:08]

I have no problem with adding a new GetDarkSuspendReadinessCallback() method but
I'm not sure I understand what you mean here.  Observers that only care about
normal suspends should not find out about dark suspends since they presumably
will not implement the DarkSuspendImminent() method.

+    // from within this method.  The returned callback should be run once the
+    // observer is ready for suspend.
+    virtual void DarkSuspendImminent() {}
+
     // Called when the power button is pressed or released.
     virtual void PowerButtonEventReceived(bool down,
                                           const base::TimeTicks& timestamp) {}