After the expiration of flag cct-retaining-state-in-memory,
SessionRestoreManger is not required.

Bug: 1456905

Change-Id: Iecd60b98b6b48e4c4b36e024f093a7994b0f1732
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4675022


Reviewed-by: Wenyu Fu <wenyufu@chromium.org>
Commit-Queue: Michael Thiessen <mthiesse@chromium.org>
Quick-Run: Shubham Gupta <shubh.gupta@samsung.com>
Cr-Commit-Position: refs/heads/main@{#1171759}