Revert "removed unnecessary defderred PrepareTpmDeviceAndFinalizeProfile"

This reverts commit 23c810e8.

Reason for revert: Suspicious about causing test failures.
https://ci.chromium.org/p/chromium/builders/ci/Linux%20ChromiumOS%20MSan%20Tests
https://ci.chromium.org/p/chromium/builders/ci/Linux%20Chromium%20OS%20ASan%20LSan%20Tests%20%281%29

Original change's description:
> removed unnecessary defderred PrepareTpmDeviceAndFinalizeProfile
>
> According to the current program flow, this to-be-removed branch seems a
> useless special handling.
>
> This CL might affect how UserSessionManager utilitzes tpm manager client
> in the near future.
>
> BUG=b:172748724
> TEST=unittests.
>
> Change-Id: I93f05a45409878db1138c8d49d835f1d7f0c427e
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2525471
> Reviewed-by: Roman Sorokin [CET] <rsorokin@chromium.org>
> Commit-Queue: Leo Lai <cylai@google.com>
> Cr-Commit-Position: refs/heads/master@{#826319}

TBR=alemate@chromium.org,rsorokin@chromium.org,khmel@chromium.org,cylai@google.com

Change-Id: If82cbaa7a634a6a33667ea139f0ec8e6f5055716
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: b:172748724
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2534273Reviewed-by: Yuki Shiino <yukishiino@chromium.org>
Commit-Queue: Yuki Shiino <yukishiino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#826698}

chrome/browser/chromeos/login/session/user_session_manager.cc

@@ -1522,6 +1522,16 @@ void UserSessionManager::UserProfileInitialized(Profile* profile,
     return;
   }
 
+  if (user_context_.GetAuthFlow() == UserContext::AUTH_FLOW_ACTIVE_DIRECTORY) {
+    // Call FinalizePrepareProfile directly and skip RestoreAuthSessionImpl
+    // because there is no need to merge session for Active Directory users.
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE,
+        base::BindOnce(&UserSessionManager::PrepareTpmDeviceAndFinalizeProfile,
+                       AsWeakPtr(), profile));
+    return;
+  }
+
   PrepareTpmDeviceAndFinalizeProfile(profile);
 }