Move pending_user_switch to SessionManager.

Moving session management out from UserManager for better
grouping of code structure.
Preparation to remove UserManager::SwitchActiveUser() family.

BUG=278643115
TEST=Tryjob

Change-Id: Iab2104027b4426642b5f053b858701bd61bc3f19
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6218325
Commit-Queue: Hidehiko Abe <hidehiko@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1415754}

components/user_manager/fake_user_manager_delegate.cc

@@ -23,10 +23,6 @@ void FakeUserManagerDelegate::OverrideDirHome(const User& primary_user) {
   NOTIMPLEMENTED();
 }
 
-bool FakeUserManagerDelegate::IsUserSessionRestoreInProgress() {
-  return false;
-}
-
 std::optional<UserType> FakeUserManagerDelegate::GetDeviceLocalAccountUserType(
     std::string_view email) {
   NOTIMPLEMENTED();

components/user_manager/fake_user_manager_delegate.h

@@ -22,7 +22,6 @@ class USER_MANAGER_EXPORT FakeUserManagerDelegate
   // UserManagerImpl::Delegate:
   const std::string& GetApplicationLocale() override;
   void OverrideDirHome(const User& primary_user) override;
-  bool IsUserSessionRestoreInProgress() override;
   std::optional<UserType> GetDeviceLocalAccountUserType(
       std::string_view email) override;
   void CheckProfileOnLogin(const User& user) override;

components/user_manager/user_manager_impl.cc

@@ -287,13 +287,6 @@ void UserManagerImpl::UserLoggedIn(const AccountId& account_id,
     SetIsCurrentUserNew(false);
     SendMultiUserSignInMetrics();
 
-    // Special case for user session restoration after browser crash.
-    // We don't switch to each user session that has been restored as once all
-    // session will be restored we'll switch to the session that has been used
-    // before the crash.
-    if (!delegate_->IsUserSessionRestoreInProgress()) {
-      pending_user_switch_ = account_id;
-    }
     NotifyUserAddedToSession(user);
 
     return;
@@ -1291,12 +1284,6 @@ void UserManagerImpl::SetOwnerId(const AccountId& owner_account_id) {
   NotifyLoginStateUpdated();
 }
 
-void UserManagerImpl::ProcessPendingUserSwitchId() {
-  if (pending_user_switch_.is_valid()) {
-    SwitchActiveUser(std::exchange(pending_user_switch_, EmptyAccountId()));
-  }
-}
-
 void UserManagerImpl::EnsureUsersLoaded() {
   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
   if (!local_state_) {
@@ -1537,7 +1524,6 @@ bool UserManagerImpl::OnUserProfileCreated(const AccountId& account_id,
 
   observer_list_.Notify(&UserManager::Observer::OnUserProfileCreated, *user);
 
-  ProcessPendingUserSwitchId();
   return true;
 }
 

components/user_manager/user_manager_impl.h

@@ -103,9 +103,6 @@ class USER_MANAGER_EXPORT UserManagerImpl : public UserManager {
     // Overrides the home directory path for the `primary_user`.
     virtual void OverrideDirHome(const User& primary_user) = 0;
 
-    // Returns whether user session restore is in progress.
-    virtual bool IsUserSessionRestoreInProgress() = 0;
-
     // Returns UserType for the DeviceLocalAccount of the given `email`.
     virtual std::optional<UserType> GetDeviceLocalAccountUserType(
         std::string_view email) = 0;
@@ -348,9 +345,6 @@ class USER_MANAGER_EXPORT UserManagerImpl : public UserManager {
   virtual void ResetOwnerId();
   void SetOwnerId(const AccountId& owner_account_id) override;
 
-  // If there's pending user switch, processes it.
-  void ProcessPendingUserSwitchId();
-
   // TODO(b/278643115): Move to private, once we migrate fake implementation
   // closer enough to the production behavior.
   void RegularUserLoggedInAsEphemeral(const AccountId& account_id,
@@ -516,10 +510,6 @@ class USER_MANAGER_EXPORT UserManagerImpl : public UserManager {
   // Time at which this object was created.
   base::TimeTicks manager_creation_time_ = base::TimeTicks::Now();
 
-  // ID of the user just added to the session that needs to be activated
-  // as soon as user's profile is loaded.
-  AccountId pending_user_switch_ = EmptyAccountId();
-
   // ID of the user that was active in the previous session.
   // Preference value is stored here before first user signs in
   // because pref will be overidden once session restore starts.