Re-land "Remove NOTIFICATION_PROFILE_ADDED from UserCloudPolicyManagerChromeOS"

This re-lands commit 00722f1e.

The change was reverted for causing unit test failures under asan.
The fix for those failures was committed as e9179a4f.
Thus, this change is identical to the original.

Original change's description:
> Remove NOTIFICATION_PROFILE_ADDED from UserCloudPolicyManagerChromeOS
>
> Use ProfileManagerObserver::OnProfileAdded instead.
>
> Also worth noting that this removes an obsolete superclass from
> UserCloudPolicyManagerChromeOS, i.e. KeyedService. Both KeyedService
> and ConfigurationPolicyProvider have a "virtual void Shutdown()"
> so this removes that collision (not that it was doing any harm).
>
> Bug: 268984,171406
> Change-Id: Ia0b3dd4dd34a0f62e84dd057928d61c5677231d5
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1854525
> Commit-Queue: Evan Stade <estade@chromium.org>
> Reviewed-by: Denis Kuznetsov <antrim@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#707909}

TBR=antrim@chromium.org

Change-Id: I9c7342b0cdf9b8d1555c27ab41ff1015633dbbf2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1874717Reviewed-by: Evan Stade <estade@chromium.org>
Commit-Queue: Evan Stade <estade@chromium.org>
Cr-Commit-Position: refs/heads/master@{#708427}

chrome/browser/chromeos/policy/user_cloud_policy_manager_chromeos.cc

@@ -19,7 +19,6 @@
 #include "base/sequenced_task_runner.h"
 #include "base/values.h"
 #include "chrome/browser/browser_process.h"
-#include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/chromeos/login/helper.h"
 #include "chrome/browser/chromeos/login/session/user_session_manager.h"
 #include "chrome/browser/chromeos/login/users/affiliation.h"
@@ -52,8 +51,6 @@
 #include "components/user_manager/user.h"
 #include "components/user_manager/user_manager.h"
 #include "content/public/browser/network_service_instance.h"
-#include "content/public/browser/notification_details.h"
-#include "content/public/browser/notification_source.h"
 #include "net/url_request/url_request_context_getter.h"
 #include "services/network/public/cpp/shared_url_loader_factory.h"
 #include "url/gurl.h"
@@ -190,9 +187,8 @@ UserCloudPolicyManagerChromeOS::UserCloudPolicyManagerChromeOS(
   // for creating the invalidator for user remote commands. The invalidator must
   // not be initialized before then because the invalidation service cannot be
   // started because it depends on components initialized at the end of profile
-  // creation.
-  registrar_.Add(this, chrome::NOTIFICATION_PROFILE_ADDED,
-                 content::Source<Profile>(profile));
+  // creation. https://crbug.com/171406
+  observed_profile_manager_.Add(g_browser_process->profile_manager());
 }
 
 void UserCloudPolicyManagerChromeOS::ForceTimeoutForTest() {
@@ -213,7 +209,7 @@ void UserCloudPolicyManagerChromeOS::SetSystemURLLoaderFactoryForTests(
   system_url_loader_factory_for_tests_ = system_url_loader_factory;
 }
 
-UserCloudPolicyManagerChromeOS::~UserCloudPolicyManagerChromeOS() {}
+UserCloudPolicyManagerChromeOS::~UserCloudPolicyManagerChromeOS() = default;
 
 void UserCloudPolicyManagerChromeOS::Connect(
     PrefService* local_state,
@@ -352,6 +348,7 @@ UserCloudPolicyManagerChromeOS::GetAppInstallEventLogUploader() {
 }
 
 void UserCloudPolicyManagerChromeOS::Shutdown() {
+  observed_profile_manager_.RemoveAll();
   app_install_event_log_uploader_.reset();
   if (client())
     client()->RemoveObserver(this);
@@ -735,16 +732,11 @@ void UserCloudPolicyManagerChromeOS::StartRefreshSchedulerIfReady() {
                                 policy_prefs::kUserPolicyRefreshRate);
 }
 
-void UserCloudPolicyManagerChromeOS::Observe(
-    int type,
-    const content::NotificationSource& source,
-    const content::NotificationDetails& details) {
-  DCHECK_EQ(chrome::NOTIFICATION_PROFILE_ADDED, type);
+void UserCloudPolicyManagerChromeOS::OnProfileAdded(Profile* profile) {
+  if (profile != profile_)
+    return;
 
-  // Now that the profile is fully created we can unsubscribe from the
-  // notification.
-  registrar_.Remove(this, chrome::NOTIFICATION_PROFILE_ADDED,
-                    content::Source<Profile>(profile_));
+  observed_profile_manager_.RemoveAll();
 
   // If true FCMInvalidationService will be used as invalidation service and
   // TiclInvalidationService otherwise.

chrome/browser/chromeos/policy/user_cloud_policy_manager_chromeos.h

@@ -14,9 +14,12 @@
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/optional.h"
+#include "base/scoped_observer.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "chrome/browser/chromeos/policy/wildcard_login_checker.h"
+#include "chrome/browser/profiles/profile_manager.h"
+#include "chrome/browser/profiles/profile_manager_observer.h"
 #include "components/account_id/account_id.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "components/keyed_service/core/keyed_service_shutdown_notifier.h"
@@ -24,8 +27,6 @@
 #include "components/policy/core/common/cloud/cloud_policy_constants.h"
 #include "components/policy/core/common/cloud/cloud_policy_manager.h"
 #include "components/policy/core/common/cloud/cloud_policy_service.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_registrar.h"
 
 class GoogleServiceAuthError;
 class PrefService;
@@ -51,8 +52,7 @@ class RemoteCommandsInvalidator;
 class UserCloudPolicyManagerChromeOS : public CloudPolicyManager,
                                        public CloudPolicyClient::Observer,
                                        public CloudPolicyService::Observer,
-                                       public content::NotificationObserver,
-                                       public KeyedService {
+                                       public ProfileManagerObserver {
  public:
   // Enum describing what behavior we want to enforce here.
   enum class PolicyEnforcement {
@@ -223,12 +223,10 @@ class UserCloudPolicyManagerChromeOS : public CloudPolicyManager,
   // call it multiple times.
   void StartRefreshSchedulerIfReady();
 
-  // content::NotificationObserver:
-  void Observe(int type,
-               const content::NotificationSource& source,
-               const content::NotificationDetails& details) override;
+  // ProfileManagerObserver:
+  void OnProfileAdded(Profile* profile) override;
 
-  // Observer called on profile shutdown.
+  // Called on profile shutdown.
   void ProfileShutdown();
 
   // Profile associated with the current user.
@@ -288,9 +286,6 @@ class UserCloudPolicyManagerChromeOS : public CloudPolicyManager,
   // injected in the constructor to make it easier to write tests.
   base::OnceClosure fatal_error_callback_;
 
-  // Used to register for notification that profile creation is complete.
-  content::NotificationRegistrar registrar_;
-
   // Invalidator used for remote commands to be delivered to this user.
   std::unique_ptr<RemoteCommandsInvalidator> invalidator_;
 
@@ -304,6 +299,9 @@ class UserCloudPolicyManagerChromeOS : public CloudPolicyManager,
   scoped_refptr<network::SharedURLLoaderFactory>
       signin_url_loader_factory_for_tests_;
 
+  ScopedObserver<ProfileManager, ProfileManagerObserver>
+      observed_profile_manager_{this};
+
   // Refresh token used in tests instead of the user context refresh token to
   // fetch the policy OAuth token.
   base::Optional<std::string> user_context_refresh_token_for_tests_;