Fix the issue that client id is not saved when upgrading the offline metadata store

components/offline_pages/offline_page_metadata_store_impl.cc

 // Copyright 2015 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/offline_pages/offline_page_metadata_store_impl.h"
 
 #include <string>
 #include <utility>
 #include <vector>
 
@@ skipping 150 matching lines @@
       // We don't want to fail the entire database if one item is corrupt,
       // so log error and keep going.
       if (!OfflinePageItemFromEntry(entry, &item)) {
         LOG(ERROR) << "failed to parse entry: " << entry.url() << " skipping.";
         continue;
       }
       // Legacy storage.  We upgrade them to the new offline_id keyed storage.
       // TODO(bburns): Remove this eventually when we are sure everyone is
       // upgraded.
       if (!entry.has_offline_id()) {
-        entry.set_offline_id(OfflinePageModel::GenerateOfflineId());
-        item.offline_id = entry.offline_id();
+        item.offline_id = OfflinePageModel::GenerateOfflineId();
 
         if (!entry.has_deprecated_bookmark_id()) {
           LOG(ERROR) << "unexpected entry missing bookmark id";
           continue;
         }
         item.client_id.name_space = offline_pages::BOOKMARK_NAMESPACE;
         item.client_id.id = base::Int64ToString(entry.deprecated_bookmark_id());
 
+        OfflinePageEntry upgraded_entry;
+        OfflinePageItemToEntry(item, &upgraded_entry);
         entries_to_update->push_back(
-            std::make_pair(base::Int64ToString(entry.offline_id()), entry));
+            std::make_pair(base::Int64ToString(upgraded_entry.offline_id()),
+                           upgraded_entry));
         keys_to_remove->push_back(item.client_id.id);

[fgorski, 2016/04/08 05:09:58]

nit: Add a comment that his is removing the old entry keyed with deprecated id.

       }
       result.push_back(item);
     }
   } else {
     status = STORE_LOAD_FAILED;
   }
 
   // If we couldn't load _anything_ report a parse failure.
   if (entries->size() > 0 && result.size() == 0) {
     status = DATA_PARSING_FAILED;
@@ skipping 112 matching lines @@
     bool success) {
   // If the update failed, log and keep going.  We'll try to
   // update next time.
   if (!success) {
     LOG(ERROR) << "Failed to update database";
   }
   NotifyLoadResult(cb, status, result);
 }
 
 }  // namespace offline_pages