Migrate ArcBridgeService::Observer and ArcSession::Observer.

chrome/browser/chromeos/arc/arc_session_manager.cc

Index: chrome/browser/chromeos/arc/arc_session_manager.cc
diff --git a/chrome/browser/chromeos/arc/arc_session_manager.cc b/chrome/browser/chromeos/arc/arc_session_manager.cc
index 28c084946b2528ad274f6ab4826f4dfd1a820c3d..209e717d0bfe4f75221a3011af6c8a2b9705cdf0 100644
--- a/chrome/browser/chromeos/arc/arc_session_manager.cc
+++ b/chrome/browser/chromeos/arc/arc_session_manager.cc
@@ -192,11 +192,10 @@ bool ArcSessionManager::IsArcKioskMode() {
   return user_manager::UserManager::Get()->IsLoggedInAsArcKioskApp();
 }
 
-void ArcSessionManager::OnBridgeStopped(ArcBridgeService::StopReason reason) {
+void ArcSessionManager::OnStopped(StopReason reason) {
   // TODO(crbug.com/625923): Use |reason| to report more detailed errors.
-  if (arc_sign_in_timer_.IsRunning()) {
+  if (arc_sign_in_timer_.IsRunning())
     OnProvisioningFinished(ProvisioningResult::ARC_STOPPED);
-  }
 
   if (profile_->GetPrefs()->GetBoolean(prefs::kArcDataRemoveRequested)) {
     // This should be always true, but just in case as this is looked at