Reduce the memory usage of bookmarks storage

components/bookmarks/browser/bookmark_storage.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/bookmarks/browser/bookmark_storage.h"
 
 #include <stddef.h>
 #include <algorithm>
 #include <utility>
 
@@ skipping 16 matching lines @@
 namespace bookmarks {
 
 namespace {
 
 // Extension used for backup files (copy of main file created during startup).
 const base::FilePath::CharType kBackupExtension[] = FILE_PATH_LITERAL("bak");
 
 // How often we save.
 const int kSaveDelayMS = 2500;
 
+// Keys in meta info of bookmark node that should be excluded after removing
+// enhanced bookmarks feature crrev.com/1638413003.
+const char* const kExcludedMetaInfoKeys[] = {"stars."};
+
 void BackupCallback(const base::FilePath& path) {
   base::FilePath backup_path = path.ReplaceExtension(kBackupExtension);
   base::CopyFile(path, backup_path);
 }
 
 // Adds node to the model's index, recursing through all children as well.
 void AddBookmarksToIndex(BookmarkLoadDetails* details,
                          BookmarkNode* node) {
   if (node->is_url()) {
     if (node->url().is_valid())
@@ skipping 15 matching lines @@
     // all bookmarks if some titles have invalid utf.
     JSONFileValueDeserializer deserializer(
         path, base::JSON_REPLACE_INVALID_CHARACTERS);
     std::unique_ptr<base::Value> root = deserializer.Deserialize(NULL, NULL);
 
     if (root.get()) {
       // Building the index can take a while, so we do it on the background
       // thread.
       int64_t max_node_id = 0;
       BookmarkCodec codec;
+      std::vector<std::string> excluded_keys;
+      excluded_keys.insert(excluded_keys.end(),
+                           std::begin(kExcludedMetaInfoKeys),
+                           std::end(kExcludedMetaInfoKeys));
+      codec.set_excluded_meta_info_keys(excluded_keys);
+
       TimeTicks start_time = TimeTicks::Now();
       codec.Decode(details->bb_node(), details->other_folder_node(),
                    details->mobile_folder_node(), &max_node_id, *root.get());
       details->set_max_id(std::max(max_node_id, details->max_id()));
       details->set_computed_checksum(codec.computed_checksum());
       details->set_stored_checksum(codec.stored_checksum());
       details->set_ids_reassigned(codec.ids_reassigned());
       details->set_model_meta_info_map(codec.model_meta_info_map());
       details->set_model_sync_transaction_version(
           codec.model_sync_transaction_version());
@@ skipping 147 matching lines @@
   }
 
   std::unique_ptr<std::string> data(new std::string);
   if (!SerializeData(data.get()))
     return false;
   writer_.WriteNow(std::move(data));
   return true;
 }
 
 }  // namespace bookmarks