[Sync] Add support for performing a GetKey on startup.

sync/sessions/status_controller.h

Index: sync/sessions/status_controller.h
diff --git a/sync/sessions/status_controller.h b/sync/sessions/status_controller.h
index 8542b48ecb2b401f97187eaae30e0306df86538b..752d07d7b31fbb137a63671b0107cc72462c33b0 100644
--- a/sync/sessions/status_controller.h
+++ b/sync/sessions/status_controller.h
@@ -149,6 +149,8 @@ class StatusController {
     return model_neutral_;
   }
 
+  SyncerError last_get_key_result() const;
+
   // A toolbelt full of methods for updating counters and flags.
   void set_num_server_changes_remaining(int64 changes_remaining);
   void set_num_successful_bookmark_commits(int value);
@@ -161,6 +163,7 @@ class StatusController {
   void increment_num_local_overwrites();
   void increment_num_server_overwrites();
   void set_sync_protocol_error(const SyncProtocolError& error);
+  void set_last_get_key_result(const SyncerError result);
   void set_last_download_updates_result(const SyncerError result);
   void set_commit_result(const SyncerError result);