arc: only suspend ARCVM after SuspendImminent

It's possible that Android calls the provided suspend callback after
SuspendDone is received, which would result in a suspended VM on
a resumed device. This CL adds a flag to check that SuspendDone was
not observed after a SuspendImminent before suspending.

Bug: b:174969196
Test: powerd_dbus_suspend
Change-Id: I1ac72bb0a88bb30c8bd3f7202f877b6d19b915b5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2578560Reviewed-by: Hidehiko Abe <hidehiko@chromium.org>
Commit-Queue: Alex Lau <alexlau@chromium.org>
Cr-Commit-Position: refs/heads/master@{#835998}

components/arc/power/arc_power_bridge.cc

@@ -178,6 +178,7 @@ void ArcPowerBridge::OnConnectionClosed() {
 
 void ArcPowerBridge::SuspendImminent(
     power_manager::SuspendImminent::Reason reason) {
+  is_suspending_ = true;
   mojom::PowerInstance* power_instance =
       ARC_GET_INSTANCE_FOR_METHOD(arc_bridge_service_->power(), Suspend);
   if (!power_instance)
@@ -191,7 +192,12 @@ void ArcPowerBridge::SuspendImminent(
 }
 
 void ArcPowerBridge::OnAndroidSuspendReady(base::UnguessableToken token) {
-  if (arc::IsArcVmEnabled()) {
+  // For the ARCVM case, we only want to suspend the VM if a suspend is still
+  // underway ie. if SuspendImminent was observed without a subsequent
+  // SuspendDone. Otherwise, skip suspending the VM but still call
+  // UnblockSuspend to fulfill the contract and to align with ARC container's
+  // behavior.
+  if (arc::IsArcVmEnabled() && is_suspending_) {
     vm_tools::concierge::SuspendVmRequest request;
     request.set_name(kArcVmName);
     request.set_owner_id(user_id_hash_);
@@ -215,6 +221,7 @@ void ArcPowerBridge::OnConciergeSuspendVmResponse(
 }
 
 void ArcPowerBridge::SuspendDone(base::TimeDelta sleep_duration) {
+  is_suspending_ = false;
   if (arc::IsArcVmEnabled()) {
     vm_tools::concierge::ResumeVmRequest request;
     request.set_name(kArcVmName);

components/arc/power/arc_power_bridge.h

@@ -141,6 +141,11 @@ class ArcPowerBridge : public KeyedService,
   // List of observers.
   base::ObserverList<Observer> observer_list_;
 
+  // Represents whether a device suspend is currently underway, ie. a
+  // SuspendImminent event has been observed, but a SuspendDone event has not
+  // yet been observed.
+  bool is_suspending_ = false;
+
   base::WeakPtrFactory<ArcPowerBridge> weak_ptr_factory_{this};
 
   DISALLOW_COPY_AND_ASSIGN(ArcPowerBridge);