Remove NOTIFICATION_SYSTEM_SETTING_CHANGED, switch CrosSettings to base::CallbackRegistry.

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 "base/bind.h"
 #include "base/callback.h"
@@ skipping 84 matching lines @@
 AttestationPolicyObserver::AttestationPolicyObserver(
     policy::CloudPolicyClient* policy_client)
     : cros_settings_(CrosSettings::Get()),
       policy_client_(policy_client),
       cryptohome_client_(NULL),
       attestation_flow_(NULL),
       num_retries_(0),
       retry_delay_(kRetryDelay),
       weak_factory_(this) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
-  cros_settings_->AddSettingsObserver(kDeviceAttestationEnabled, this);
+  attestation_subscription_ = cros_settings_->AddSettingsObserver(
+      kDeviceAttestationEnabled,
+      base::Bind(&AttestationPolicyObserver::AttestationSettingChanged,
+                 base::Unretained(this)));
   Start();
 }
 
 AttestationPolicyObserver::AttestationPolicyObserver(
     policy::CloudPolicyClient* policy_client,
     CryptohomeClient* cryptohome_client,
     AttestationFlow* attestation_flow)
     : cros_settings_(CrosSettings::Get()),
       policy_client_(policy_client),
       cryptohome_client_(cryptohome_client),
       attestation_flow_(attestation_flow),
       num_retries_(0),
       retry_delay_(kRetryDelay),
       weak_factory_(this) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
-  cros_settings_->AddSettingsObserver(kDeviceAttestationEnabled, this);
+  attestation_subscription_ = cros_settings_->AddSettingsObserver(
+      kDeviceAttestationEnabled,
+      base::Bind(&AttestationPolicyObserver::AttestationSettingChanged,
+                 base::Unretained(this)));
   Start();
 }
 
 AttestationPolicyObserver::~AttestationPolicyObserver() {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
-  cros_settings_->RemoveSettingsObserver(kDeviceAttestationEnabled, this);
 }
 
-void AttestationPolicyObserver::Observe(
-    int type,
-    const content::NotificationSource& source,
-    const content::NotificationDetails& details) {
-  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));

[Darren Krahn, 2013/09/18 09:05:37]

Was removing this DCHECK intentional?  If so, we may want to schedule the
Start() call below on the UI thread.

[Avi (use Gerrit), 2013/09/18 16:41:44]

Not intentional. I'll re-insert.

-  std::string* path = content::Details<std::string>(details).ptr();
-  if (type != chrome::NOTIFICATION_SYSTEM_SETTING_CHANGED ||
-      *path != kDeviceAttestationEnabled) {
-    LOG(WARNING) << "AttestationPolicyObserver: Unexpected event received.";
-    return;
-  }
+void AttestationPolicyObserver::AttestationSettingChanged() {
   num_retries_ = 0;
   Start();
 }
 
 void AttestationPolicyObserver::Start() {
   // If attestation is not enabled, there is nothing to do.
   bool enabled = false;
   if (!cros_settings_->GetBoolean(kDeviceAttestationEnabled, &enabled) ||
       !enabled)
     return;
@@ skipping 154 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