Libcros changes for issue_12743: Add async RequestUpdateCheck call.

load.cc

Index: load.cc
diff --git a/load.cc b/load.cc
index 4b4dec34dc928a0a065a428cfda462580430b0b8..4457387c0a7893ff2901ee27d443080843314f58 100644
--- a/load.cc
+++ b/load.cc
@@ -368,6 +368,7 @@ DECL_FUNC_2(MonitorUpdateStatus, UpdateStatusConnection, UpdateMonitor, void*);
 DECL_FUNC_1(DisconnectUpdateProgress, void, UpdateStatusConnection);
 DECL_FUNC_1(RetrieveUpdateProgress, bool, UpdateProgress*);
 DECL_FUNC_0(InitiateUpdateCheck, bool);
+DECL_FUNC_2(RequestUpdateCheck, void, UpdateCallback, void*);
 DECL_FUNC_0(RebootIfUpdated, bool);
 DECL_FUNC_1(SetTrack, bool, const std::string&);
 DECL_FUNC_0(GetTrack, std::string);
@@ -647,6 +648,7 @@ bool LoadLibcros(const char* path_to_libcros, std::string& error_string) {
   INIT_FUNC(DisconnectUpdateProgress);
   INIT_FUNC(RetrieveUpdateProgress);
   INIT_FUNC(InitiateUpdateCheck);
+  INIT_FUNC(RequestUpdateCheck);
   INIT_FUNC(RebootIfUpdated);
   INIT_FUNC(SetTrack);
   INIT_FUNC(GetTrack);