Do not submit: high level overview patch.

chrome/browser/sessions/persistent_tab_restore_service.cc

Index: chrome/browser/sessions/persistent_tab_restore_service.cc
diff --git a/chrome/browser/sessions/persistent_tab_restore_service.cc b/chrome/browser/sessions/persistent_tab_restore_service.cc
index d8df61b4bb9f9d367999cd88be363579823d9336..dd03b0aee2edbb7f4dd9829cadec1f9c4fbc9b46 100644
--- a/chrome/browser/sessions/persistent_tab_restore_service.cc
+++ b/chrome/browser/sessions/persistent_tab_restore_service.cc
@@ -102,6 +102,7 @@ const SessionCommand::id_type kCommandPinnedState = 5;
 const SessionCommand::id_type kCommandSetExtensionAppID = 6;
 const SessionCommand::id_type kCommandSetWindowAppName = 7;
 const SessionCommand::id_type kCommandSetTabUserAgentOverride = 8;
+const SessionCommand::id_type kCommandSetTabSessionSyncId = 9;
 
 // Number of entries (not commands) before we clobber the file and write
 // everything.
@@ -455,6 +456,11 @@ void PersistentTabRestoreService::Delegate::ScheduleCommandsForTab(
                                              tab.id, tab.user_agent_override));
   }
 
+  if (tab.sync_session_id != -1) {
+    ScheduleCommand(CreateSetTabSessionSyncIdCommand(
+        kCommandSetTabSessionSyncId, tab.id, tab.sync_session_id));
+  }
+
   // Then write the navigations.
   for (int i = first_index_to_persist, wrote_count = 0;
        i < max_index && wrote_count < 2 * max_persist_navigation_count; ++i) {
@@ -735,6 +741,21 @@ void PersistentTabRestoreService::Delegate::CreateEntriesFromCommands(
         break;
       }
 
+      case kCommandSetTabSessionSyncId: {
+        if (!current_tab) {
+          // Should be in a tab when we get this.
+          return;
+        }
+        SessionID::id_type tab_id;
+        int64 sync_id;
+        if (!RestoreSetTabSessionSyncIdCommand(command, &tab_id, &sync_id)) {
+          current_tab->sync_session_id = sync_id;
+          return;
+        }
+        current_tab->sync_session_id = sync_id;
+        break;
+      }
+
       default:
         // Unknown type, usually indicates corruption of file. Ignore it.
         return;
@@ -792,6 +813,7 @@ bool PersistentTabRestoreService::Delegate::ConvertSessionWindowToWindow(
       tab.current_navigation_index =
           session_window->tabs[i]->current_navigation_index;
       tab.extension_app_id = session_window->tabs[i]->extension_app_id;
+      tab.sync_session_id = session_window->tabs[i]->sync_session_id;
       tab.timestamp = base::Time();
     }
   }