Remove obsolete TODOs from the user event and consent sync bridges

Bug: 851439
Change-Id: Id955ccd91aa234c9a81566c0c76568e30d9d54ac
Reviewed-on: https://chromium-review.googlesource.com/c/1346396Reviewed-by: vitaliii <vitaliii@chromium.org>
Commit-Queue: Marc Treib <treib@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610065}

components/consent_auditor/consent_sync_bridge_impl.cc

@@ -248,8 +248,6 @@ void ConsentSyncBridgeImpl::OnStoreCreated(
     return;
   }
 
-  // TODO(vitaliii): Garbage collect old consents if sync is disabled.
-
   store_ = std::move(store);
   store_->ReadAllMetadata(
       base::BindOnce(&ConsentSyncBridgeImpl::OnReadAllMetadata,

components/sync/user_events/user_event_sync_bridge.cc

@@ -322,8 +322,6 @@ void UserEventSyncBridge::OnStoreCreated(
     return;
   }
 
-  // TODO(vitaliii): Garbage collect old user consents if sync is disabled.
-
   store_ = std::move(store);
   store_->ReadAllMetadata(base::BindOnce(
       &UserEventSyncBridge::OnReadAllMetadata, weak_ptr_factory_.GetWeakPtr()));