Remove comment about DB maintenance

crrev.com/c/4891458 added a `storage_size` column to store the
EstimatedSize() upon each join and update, so this comment is no
longer true.

Change-Id: I87c50e231e35d80f35061713d2c24591f71e4bb7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5941090
Reviewed-by: Russ Hamilton <behamilton@google.com>
Commit-Queue: Russ Hamilton <behamilton@google.com>
Auto-Submit: Caleb Raitto <caraitto@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1370712}

content/browser/interest_group/interest_group_storage.cc

@@ -5106,11 +5106,7 @@ bool ClearExpiredInterestGroups(sql::Database& db,
   return transaction.Commit();
 }
 
-// Removes interest groups so that per-owner limit is respected. Note that
-// we're intentionally not trying to keep this in sync with
-// `blink::InterestGroup::EstimateSize()`. There's not a compelling reason to
-// keep those exactly aligned and keeping them in sync would require a
-// significant amount of extra work.
+// Removes interest groups so that per-owner limit is respected.
 bool ClearExcessiveStorage(sql::Database& db, size_t max_owner_storage_size) {
   sql::Transaction transaction(&db);
   if (!transaction.Begin()) {