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..827afffcb89c186447bd3aea75d47a2dbbe87f88 100644
--- a/components/bookmarks/browser/bookmark_codec.h
+++ b/components/bookmarks/browser/bookmark_codec.h
@@ -7,6 +7,7 @@
 
 #include <stdint.h>
 
+#include <list>
 #include <memory>
 #include <set>
 #include <string>
@@ -87,6 +88,10 @@ class BookmarkCodec {
   // false after encoding.
   bool ids_reassigned() const { return ids_reassigned_; }
 
+  void set_excluded_meta_info_keys(const std::list<const char*>& keys) {
+    excluded_meta_info_keys_ = keys;
+  }
+
   // Names of the various keys written to the Value.
   static const char kRootsKey[];
   static const char kRootFolderNameKey[];
@@ -205,6 +210,8 @@ class BookmarkCodec {
   // Sync transaction version set on bookmark model root.
   int64_t model_sync_transaction_version_;
 
+  std::list<const char*> excluded_meta_info_keys_;
+
   DISALLOW_COPY_AND_ASSIGN(BookmarkCodec);
 };