[Sync] Remove obsolete feature toggles

This CL removes following feature toggles as they were enabled by
default in M83 or earlier:
* InvalidateBookmarkSyncMetadataIfClientTagDuplicates
* SyncScheduleForEntityMetadataChangesOnly

Bug: 1114738
Change-Id: Ic15e946e52124d49e28343e0969ffe0ed4931cb2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2346654
Commit-Queue: Rushan Suleymanov <rushans@google.com>
Commit-Queue: Marc Treib <treib@chromium.org>
Auto-Submit: Rushan Suleymanov <rushans@google.com>
Reviewed-by: Marc Treib <treib@chromium.org>
Cr-Commit-Position: refs/heads/master@{#796787}

components/sync_bookmarks/bookmark_model_type_processor.cc

@@ -80,15 +80,6 @@ void LogMissingPermanentNodes(
                             missing_nodes);
 }
 
-// Enables scheduling bookmark model saving only upon changes in entity sync
-// metadata. This would stop persisting changes to the model type state that
-// doesn't involve changes to the entity metadata as well.
-// TODO(crbug.com/945820): This should be removed in M80 if not issues are
-// observed.
-const base::Feature kSyncScheduleForEntityMetadataChangesOnly{
-    "SyncScheduleForEntityMetadataChangesOnly",
-    base::FEATURE_ENABLED_BY_DEFAULT};
-
 class ScopedRemoteUpdateBookmarks {
  public:
   // |bookmark_model|, |bookmark_undo_service| and |observer| must not be null
@@ -252,8 +243,7 @@ void BookmarkModelTypeProcessor::OnUpdateReceived(
   // There are cases when we receive non-empty updates that don't result in
   // model changes (e.g. reflections). In that case, issue a write to persit the
   // progress marker in order to avoid downloading those updates again.
-  if (!updates.empty() || !base::FeatureList::IsEnabled(
-                              kSyncScheduleForEntityMetadataChangesOnly)) {
+  if (!updates.empty()) {
     // Schedule save just in case one is needed.
     schedule_save_closure_.Run();
   }

components/sync_bookmarks/synced_bookmark_tracker.cc

@@ -31,10 +31,6 @@ const base::Feature kInvalidateBookmarkSyncMetadataIfMismatchingGuid{
     "InvalidateBookmarkSyncMetadataIfMismatchingGuid",
     base::FEATURE_ENABLED_BY_DEFAULT};
 
-extern const base::Feature kInvalidateBookmarkSyncMetadataIfClientTagDuplicates{
-    "InvalidateBookmarkSyncMetadataIfClientTagDuplicates",
-    base::FEATURE_ENABLED_BY_DEFAULT};
-
 // TODO(crbug.com/1032052): Enable by default once UMA metric
 // Sync.BookmarkModelMetadataClientTagState suggests that most users have
 // received client tag hashes (final GUIDs).
@@ -581,9 +577,7 @@ SyncedBookmarkTracker::InitEntitiesFromModelAndMetadata(
               bookmark_metadata.metadata().client_tag_hash());
       const bool new_element =
           used_client_tag_hashes.insert(client_tag_hash).second;
-      if (!new_element &&
-          base::FeatureList::IsEnabled(
-              kInvalidateBookmarkSyncMetadataIfClientTagDuplicates)) {
+      if (!new_element) {
         DLOG(ERROR) << "Error when decoding sync metadata: Duplicated client "
                        "tag hash.";
         return CorruptionReason::DUPLICATED_CLIENT_TAG_HASH;