Do not submit: high level overview patch.

chrome/browser/sessions/base_session_service.cc

Index: chrome/browser/sessions/base_session_service.cc
diff --git a/chrome/browser/sessions/base_session_service.cc b/chrome/browser/sessions/base_session_service.cc
index 64c094c7e4ffe4a887f95006745bfa6a91b69162..7cdcb6e6b026a2a1ffb5c1fa5d71160d83a18559 100644
--- a/chrome/browser/sessions/base_session_service.cc
+++ b/chrome/browser/sessions/base_session_service.cc
@@ -219,6 +219,18 @@ SessionCommand* BaseSessionService::CreateSetWindowAppNameCommand(
   return new SessionCommand(command_id, pickle);
 }
 
+SessionCommand* BaseSessionService::CreateSetTabSessionSyncIdCommand(
+    SessionID::id_type command_id,
+    SessionID::id_type tab_id,
+    const int64& sync_id) {
+  // Use pickle to handle marshalling.
+  Pickle pickle;
+  pickle.WriteInt(tab_id);
+  pickle.WriteInt64(sync_id);
+
+  return new SessionCommand(command_id, pickle);
+}
+
 bool BaseSessionService::RestoreUpdateTabNavigationCommand(
     const SessionCommand& command,
     sessions::SerializedNavigationEntry* navigation,
@@ -271,6 +283,19 @@ bool BaseSessionService::RestoreSetWindowAppNameCommand(
       pickle->ReadString(&iterator, app_name);
 }
 
+bool BaseSessionService::RestoreSetTabSessionSyncIdCommand(
+    const SessionCommand& command,
+    SessionID::id_type* tab_id,
+    int64* sync_id) {
+  scoped_ptr<Pickle> pickle(command.PayloadAsPickle());
+  if (!pickle.get())
+    return false;
+
+  PickleIterator iterator(*pickle);
+  return pickle->ReadInt(&iterator, tab_id) &&
+         pickle->ReadInt64(&iterator, sync_id);
+}
+
 bool BaseSessionService::ShouldTrackEntry(const GURL& url) {
   return url.is_valid();
 }