[GCM] Minimum change for periodic checkin

google_apis/gcm/engine/gcm_store_impl.h

Index: google_apis/gcm/engine/gcm_store_impl.h
diff --git a/google_apis/gcm/engine/gcm_store_impl.h b/google_apis/gcm/engine/gcm_store_impl.h
index 971367a8bf01960fad72894a6f4dc453a99f0c0c..a08a72c624235e24789c1e9f827a437caac219f0 100644
--- a/google_apis/gcm/engine/gcm_store_impl.h
+++ b/google_apis/gcm/engine/gcm_store_impl.h
@@ -74,6 +74,10 @@ class GCM_EXPORT GCMStoreImpl : public GCMStore {
   virtual void RemoveOutgoingMessages(const PersistentIdList& persistent_ids,
                                       const UpdateCallback& callback) OVERRIDE;
 
+  // Sets last device's checkin time.
+  virtual void SetLastCheckinTime(const base::Time& last_checkin_time,
+                                  const UpdateCallback& callback) OVERRIDE;
+
  private:
   typedef std::map<std::string, int> AppIdToMessageCountMap;