[Sync] Add histograms for cookie jar state on Sessions commit

sync/internal_api/public/sync_manager.h

Index: sync/internal_api/public/sync_manager.h
diff --git a/sync/internal_api/public/sync_manager.h b/sync/internal_api/public/sync_manager.h
index aca4ca09fcadf9acf9847e2ba5d03c6c857242db..ec630acb8f0faeaf367640403a282a9a22f8b95f 100644
--- a/sync/internal_api/public/sync_manager.h
+++ b/sync/internal_api/public/sync_manager.h
@@ -409,7 +409,7 @@ class SYNC_EXPORT SyncManager {
   // Updates Sync's tracking of whether the cookie jar has a mismatch with the
   // chrome account. See ClientConfigParams proto message for more info.
   // Note: this does not trigger a sync cycle. It just updates the sync context.
-  virtual void OnCookieJarChanged(bool account_mismatch) = 0;
+  virtual void OnCookieJarChanged(bool account_mismatch, bool empty_jar) = 0;
 };
 
 }  // namespace syncer