Remove the "not_after" validation of policy timestamps

chrome/browser/chromeos/settings/session_manager_operation.cc

Index: chrome/browser/chromeos/settings/session_manager_operation.cc
diff --git a/chrome/browser/chromeos/settings/session_manager_operation.cc b/chrome/browser/chromeos/settings/session_manager_operation.cc
index bdd59b682604b57aaa68928efe06238c1b53b84c..9fe4f04c0493f45f760937e03deaed288cfa3321 100644
--- a/chrome/browser/chromeos/settings/session_manager_operation.cc
+++ b/chrome/browser/chromeos/settings/session_manager_operation.cc
@@ -170,17 +170,7 @@ void SessionManagerOperation::ValidateDeviceSettings(
 
   if (cloud_validations_) {
     // Policy auto-generated by session manager doesn't include a timestamp, so
-    // the timestamp shouldn't be verified in that case.
-    //
-    // Additionally, offline devices can get their clock set backwards in time
-    // under some hardware conditions; checking the timestamp now could likely
-    // find a value in the future, and prevent the user from signing-in or
-    // starting guest mode. Tlsdate will eventually fix the clock when the
-    // device is back online, but the network configuration may come from device
-    // ONC.
-    //
-    // To prevent all of these issues the timestamp is just not verified when
-    // loading the device policy from session manager. Note that the timestamp
+    // the timestamp shouldn't be verified in that case. Note that the timestamp
     // is still verified during enrollment and when a new policy is fetched from
     // the server.
     //