Fix DCHECK in ReadingListEntry.

components/reading_list/core/reading_list_entry.cc

Index: components/reading_list/core/reading_list_entry.cc
diff --git a/components/reading_list/core/reading_list_entry.cc b/components/reading_list/core/reading_list_entry.cc
index 25956e367ba40f24b9ca6d615cb554c43c7e4f07..8e3af18155b6f46130daf6ab6540f6de09b5ecd8 100644
--- a/components/reading_list/core/reading_list_entry.cc
+++ b/components/reading_list/core/reading_list_entry.cc
@@ -302,10 +302,15 @@ std::unique_ptr<ReadingListEntry> ReadingListEntry::FromReadingListLocal(
     update_time_us = pb_entry.update_time_us();
   }
 
-  int64_t update_title_time_us = creation_time_us;
+  int64_t update_title_time_us = 0;
   if (pb_entry.has_update_title_time_us()) {
     update_title_time_us = pb_entry.update_title_time_us();
   }
+  if (update_title_time_us == 0) {
+    // Entries created before title could be modified don't have
+    // update_title_time_us. Set it to creation_time_us for consistency.
+    update_title_time_us = creation_time_us;
+  }
 
   State state = UNSEEN;
   if (pb_entry.has_status()) {
@@ -418,10 +423,15 @@ std::unique_ptr<ReadingListEntry> ReadingListEntry::FromReadingListSpecifics(
     update_time_us = pb_entry.update_time_us();
   }
 
-  int64_t update_title_time_us = creation_time_us;
+  int64_t update_title_time_us = 0;
   if (pb_entry.has_update_title_time_us()) {
     update_title_time_us = pb_entry.update_title_time_us();
   }
+  if (update_title_time_us == 0) {
+    // Entries created before title could be modified don't have
+    // update_title_time_us. Set it to creation_time_us for consistency.
+    update_title_time_us = creation_time_us;
+  }
 
   State state = UNSEEN;
   if (pb_entry.has_status()) {