Reduce the memory usage of bookmarks storage

components/bookmarks/browser/bookmark_codec.h

Index: components/bookmarks/browser/bookmark_codec.h
diff --git a/components/bookmarks/browser/bookmark_codec.h b/components/bookmarks/browser/bookmark_codec.h
index 7760826e4f61d7769fe907a2b9f639f5e953e211..e6ecee2f369786c7f587b7bdd21bbc3c6e244060 100644
--- a/components/bookmarks/browser/bookmark_codec.h
+++ b/components/bookmarks/browser/bookmark_codec.h
@@ -7,9 +7,11 @@
 
 #include <stdint.h>
 
+#include <list>
 #include <memory>
 #include <set>
 #include <string>
+#include <vector>
 
 #include "base/macros.h"
 #include "base/md5.h"
@@ -87,6 +89,10 @@ class BookmarkCodec {
   // 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[];
@@ -205,6 +211,8 @@ class BookmarkCodec {
   // 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);
 };