Clean up some stale TODOs and comments

Bug: 723854
Change-Id: I6cb7a4c60dd458c76d59019175c04984e0b75abc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1904757Reviewed-by: Hiroshi Ichikawa <ichikawa@chromium.org>
Commit-Queue: John Wu <jzw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#713884}

ios/web_view/internal/app/application_context.mm

@@ -72,7 +72,6 @@ void ApplicationContext::PreCreateThreads() {
 
 void ApplicationContext::SaveState() {
   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
-  // TODO(crbug.com/723854): Commit prefs when entering background.
   if (local_state_) {
     local_state_->CommitPendingWrite();
   }

ios/web_view/internal/autofill/cwv_credit_card_saver.mm

@@ -113,7 +113,6 @@ NSArray<NSAttributedString*>* CWVLegalMessagesFromLegalMessageLines(
 
     _saveCompletionHandler = completionHandler;
     DCHECK(_uploadSaveCardCallback);
-    // TODO(crbug.com/993130): Provide additional card details if required.
     std::move(_uploadSaveCardCallback)
         .Run(autofill::AutofillClient::ACCEPTED,
              /*user_provided_card_details=*/{});

ios/web_view/internal/sync/web_view_sync_client.mm

@@ -135,7 +135,7 @@ base::RepeatingClosure WebViewSyncClient::GetPasswordStateChangedCallback() {
 syncer::DataTypeController::TypeVector
 WebViewSyncClient::CreateDataTypeControllers(
     syncer::SyncService* sync_service) {
-  // iOS WebView uses butter sync and so has no need to record user consents.
+  // //ios/web_view clients are supposed to record their own consents.
   syncer::DataTypeController::TypeVector type_vector =
       component_factory_->CreateCommonDataTypeControllers(GetDisabledTypes(),
                                                           sync_service);