Reduce the memory usage of bookmarks storage

components/bookmarks/browser/bookmark_codec.h

 // 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.
 
 #ifndef COMPONENTS_BOOKMARKS_BROWSER_BOOKMARK_CODEC_H_
 #define COMPONENTS_BOOKMARKS_BROWSER_BOOKMARK_CODEC_H_
 
 #include <stdint.h>
 
+#include <list>
 #include <memory>
 #include <set>
 #include <string>
+#include <vector>
 
 #include "base/macros.h"
 #include "base/md5.h"
 #include "base/strings/string16.h"
 #include "components/bookmarks/browser/bookmark_node.h"
 
 namespace base {
 class DictionaryValue;
 class ListValue;
 class Value;
@@ skipping 57 matching lines @@
 
   // Return the sync transaction version of the bookmark model root.
   int64_t model_sync_transaction_version() const {
     return model_sync_transaction_version_;
   }
 
   // Returns whether the IDs were reassigned during decoding. Always returns
   // false after encoding.
   bool ids_reassigned() const { return ids_reassigned_; }
 
+  void set_excluded_meta_info_keys(const std::vector<std::string>& keys) {

[sky, 2017/05/26 03:07:38]

Wouldn't a set be a better data structure here?

[sky, 2017/05/26 03:07:39]

Be consistent: meta_data_keys_.

[ssid, 2017/05/30 21:39:14]

I think meta_info is consistent with DecodeMetaInfo and SetMetaInfo and friends.

[ssid, 2017/05/30 21:39:14]

set uses around 4 extra pointers for each element present. We only use this
container for iteration and not for searching. vector is cheaper.

+    excluded_meta_info_keys_ = keys;
+  }
+
   // Names of the various keys written to the Value.
   static const char kRootsKey[];
   static const char kRootFolderNameKey[];
   static const char kOtherBookmarkFolderNameKey[];
   static const char kMobileBookmarkFolderNameKey[];
   static const char kVersionKey[];
   static const char kChecksumKey[];
   static const char kIdKey[];
   static const char kTypeKey[];
   static const char kNameKey[];
@@ skipping 98 matching lines @@
 
   // Maximum ID assigned when decoding data.
   int64_t maximum_id_;
 
   // Meta info set on bookmark model root.
   BookmarkNode::MetaInfoMap model_meta_info_map_;
 
   // Sync transaction version set on bookmark model root.
   int64_t model_sync_transaction_version_;
 
+  std::vector<std::string> excluded_meta_info_keys_;
+
   DISALLOW_COPY_AND_ASSIGN(BookmarkCodec);
 };
 
 }  // namespace bookmarks
 
 #endif  // COMPONENTS_BOOKMARKS_BROWSER_BOOKMARK_CODEC_H_