Created AttestationPolicyObserver.

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 "chrome/browser/policy/cloud/cloud_policy_client.h"
+#include "chrome/browser/policy/cloud/cloud_policy_manager.h"
+#include "chrome/common/chrome_notification_types.h"
+#include "content/public/browser/notification_details.h"
+
+using std::string;
+
+namespace chromeos {
+namespace attestation {
+
+AttestationPolicyObserver::AttestationPolicyObserver(
+    CrosSettings* settings,
+    policy::CloudPolicyManager* policy_manager,

[Mattias Nissler (ping if slow), 2013/03/27 14:16:34]

Just pass a CloudPolicyClient pointer if that's all you need? I guess I'm
missing context on who's going to use this observer object, where it gets
instantiated etc.

[dkrahn, 2013/03/27 21:20:44]

From my reading of the code (correct me if I'm wrong) when this object is
initialized the client does not yet exist, but it should exist when a settings
change event is received.  If we change where this class is instantiated then
this can change.

[Mattias Nissler (ping if slow), 2013/04/02 12:49:39]

You're right about the CloudPolicyClient not necessarily being available. I
guess the question becomes: What is the correct lifetime for this object? Should
it hold CloudPolicyClient* pointer at all?

Have you thought about moving ownership of AttestationPolicyObserver to
DeviceCloudPolicyManagerChromeOS, and then have it call Connect() here after it
created a CloudPolicyClient?

[dkrahn, 2013/04/04 21:27:26]

Moved to DeviceCloudPolicyManagerChromeOS and added a Connect method.

+    scoped_ptr<AttestationFlow> attestation_flow)
+    : settings_(settings),
+      policy_manager_(policy_manager),
+      attestation_flow_(attestation_flow.Pass()) {
+  settings_->AddSettingsObserver(kDeviceAttestationEnabled, this);
+}
+
+AttestationPolicyObserver::~AttestationPolicyObserver() {
+  settings_->RemoveSettingsObserver(kDeviceAttestationEnabled, this);
+}
+
+void AttestationPolicyObserver::Observe(
+    int type,
+    const content::NotificationSource& source,
+    const content::NotificationDetails& details) {
+  string* path = content::Details<string>(details).ptr();
+  if (type != chrome::NOTIFICATION_SYSTEM_SETTING_CHANGED ||
+      *path != kDeviceAttestationEnabled) {
+    LOG(WARNING) << "AttestationPolicyObserver: Unexpected event received.";
+    return;
+  }
+
+  // If attestation is not enabled, there is nothing to do.
+  bool enabled = false;
+  if (!settings_->GetBoolean(kDeviceAttestationEnabled, &enabled) || !enabled)
+    return;
+
+  // We need a valid CloudPolicyClient to proceed.
+  policy::CloudPolicyClient* client = policy_manager_->core()->client();
+  if (!client) {
+    LOG(ERROR) << "AttestationPolicyObserver: Invalid CloudPolicyClient.";
+    return;
+  }
+
+  // TODO(dkrahn): Generate EMK and upload EMCert if necessary.

[Mattias Nissler (ping if slow), 2013/03/27 14:16:34]

Are you meaning to commit this in the half-baked state here?

[dkrahn, 2013/03/27 21:20:44]

Yes.  Before I do a lot of work I want your +1 that I'm on the right track,
using the right objects, etc..

[Mattias Nissler (ping if slow), 2013/04/02 12:49:39]

Hard for me to figure out with significant pieces missing, but I'll do my very
best :)

[dkrahn, 2013/04/04 21:27:26]

I've added more meat here, although there are still a few missing parts.  Unit
tests have also been added.

+}
+
+}  // namespace attestation
+}  // namespace chromeos