Make CloudPolicyValidator memory management clearer

chrome/browser/chromeos/policy/user_cloud_policy_store_chromeos.cc

 // Copyright (c) 2012 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/policy/user_cloud_policy_store_chromeos.h"
 
 #include <stddef.h>
 #include <utility>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/files/file_util.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/macros.h"
+#include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/sequenced_task_runner.h"
 #include "base/stl_util.h"
 #include "base/strings/stringprintf.h"
 #include "chrome/browser/chromeos/policy/user_policy_token_loader.h"
 #include "chromeos/cryptohome/cryptohome_parameters.h"
 #include "chromeos/dbus/cryptohome_client.h"
 #include "chromeos/dbus/session_manager_client.h"
 #include "components/policy/core/common/cloud/cloud_policy_constants.h"
 #include "components/policy/proto/cloud_policy.pb.h"
@@ skipping 127 matching lines @@
   std::unique_ptr<UserCloudPolicyValidator> validator = CreateValidator(
       std::move(policy), CloudPolicyValidatorBase::TIMESTAMP_FULLY_VALIDATED);
   validator->ValidateUsername(account_id_.GetUserEmail(), true);
   if (cached_policy_key_.empty()) {
     validator->ValidateInitialKey(ExtractDomain(account_id_.GetUserEmail()));
   } else {
     validator->ValidateSignatureAllowingRotation(
         cached_policy_key_, ExtractDomain(account_id_.GetUserEmail()));
   }
 
-  // Start validation. The Validator will delete itself once validation is
-  // complete.
-  validator.release()->StartValidation(
+  // Start validation.
+  UserCloudPolicyValidator::StartValidation(
+      std::move(validator),
       base::Bind(&UserCloudPolicyStoreChromeOS::OnPolicyToStoreValidated,
                  weak_factory_.GetWeakPtr()));
 }
 
 void UserCloudPolicyStoreChromeOS::OnPolicyToStoreValidated(
     UserCloudPolicyValidator* validator) {
   DCHECK(!is_active_directory_);
 
   validation_status_ = validator->status();
 
@@ skipping 61 matching lines @@
     ValidateRetrievedPolicy(std::move(policy));
   } else {
     EnsurePolicyKeyLoaded(
         base::Bind(&UserCloudPolicyStoreChromeOS::ValidateRetrievedPolicy,
                    weak_factory_.GetWeakPtr(), base::Passed(&policy)));
   }
 }
 
 void UserCloudPolicyStoreChromeOS::ValidateRetrievedPolicy(
     std::unique_ptr<em::PolicyFetchResponse> policy) {
-  // Create and configure a validator for the loaded policy.
-  std::unique_ptr<UserCloudPolicyValidator> validator =
-      CreateValidatorForLoad(std::move(policy));
-  // Start validation. The Validator will delete itself once validation is
-  // complete.
-  validator.release()->StartValidation(
+  UserCloudPolicyValidator::StartValidation(
+      CreateValidatorForLoad(std::move(policy)),
       base::Bind(&UserCloudPolicyStoreChromeOS::OnRetrievedPolicyValidated,
                  weak_factory_.GetWeakPtr()));
 }
 
 void UserCloudPolicyStoreChromeOS::OnRetrievedPolicyValidated(
     UserCloudPolicyValidator* validator) {
   validation_status_ = validator->status();
 
   UMA_HISTOGRAM_ENUMERATION(
       "Enterprise.UserPolicyValidationLoadStatus",
@@ skipping 111 matching lines @@
     validator->ValidateUsername(account_id_.GetUserEmail(), true);
     // The policy loaded from session manager need not be validated using the
     // verification key since it is secure, and since there may be legacy policy
     // data that was stored without a verification key.
     validator->ValidateSignature(cached_policy_key_);
   }
   return validator;
 }
 
 }  // namespace policy