Wait for the attestation to be ready (TPM being prepared for attestation) before trying to enroll.

chrome/browser/chromeos/attestation/attestation_policy_observer.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chromeos/attestation/attestation_policy_observer.h"
 
 #include <string>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 144 matching lines @@
   }
 
   if (!cryptohome_client_)
     cryptohome_client_ = DBusThreadManager::Get()->GetCryptohomeClient();
 
   if (!attestation_flow_) {
     std::unique_ptr<ServerProxy> attestation_ca_client(
         new AttestationCAClient());
     default_attestation_flow_.reset(new AttestationFlow(
         cryptohome::AsyncMethodCaller::GetInstance(), cryptohome_client_,
-        std::move(attestation_ca_client)));
+        std::move(attestation_ca_client), base::TimeDelta::FromMinutes(1)));

[apronin1, 2016/12/05 19:25:50]

here and other places where constructor is called:

Didn't you plan to go with some default value suggested by AttestationFlow
itself?

I thought it was going to be something like AttestationFlow::DefaultTimeout (and
TimeDelta::Max() where you are ok with waiting as long as it takes).
FromMinutes(1) sounds to be somewhat random.

     attestation_flow_ = default_attestation_flow_.get();
   }
 
   // Start a dbus call to check if an Enterprise Machine Key already exists.
   base::Closure on_does_exist =
       base::Bind(&AttestationPolicyObserver::GetExistingCertificate,
                  weak_factory_.GetWeakPtr());
   base::Closure on_does_not_exist =
       base::Bind(&AttestationPolicyObserver::GetNewCertificate,
                  weak_factory_.GetWeakPtr());
@@ skipping 138 matching lines @@
         base::Bind(&AttestationPolicyObserver::Start,
                    weak_factory_.GetWeakPtr()),
         base::TimeDelta::FromSeconds(retry_delay_));
   } else {
     LOG(WARNING) << "AttestationPolicyObserver: Retry limit exceeded.";
   }
 }
 
 }  // namespace attestation
 }  // namespace chromeos