Add logic to flip Nigori bit to instruct other clients to sync tabs.

chrome/browser/sync/internal_api/sync_manager.h

Index: chrome/browser/sync/internal_api/sync_manager.h
diff --git a/chrome/browser/sync/internal_api/sync_manager.h b/chrome/browser/sync/internal_api/sync_manager.h
index 2dfe1259170ce337e09796d94877abb854762b30..b8f43a46aba28c864fb976d50a0bd877269272eb 100644
--- a/chrome/browser/sync/internal_api/sync_manager.h
+++ b/chrome/browser/sync/internal_api/sync_manager.h
@@ -434,6 +434,10 @@ class SyncManager {
   // Called when the user disables or enables a sync type.
   void UpdateEnabledTypes();
 
+  // Conditionally sets the flag in the Nigori node which instructs other
+  // clients to start syncing tabs.
+  void MaybeSetSyncTabsInNigoriNode(const syncable::ModelTypeSet enabled_types);
+
   // Put the syncer in normal mode ready to perform nudges and polls.
   void StartSyncingNormally();