[GCM] fixing G-settings initialization from an empty store

google_apis/gcm/engine/gservices_settings.h

Index: google_apis/gcm/engine/gservices_settings.h
diff --git a/google_apis/gcm/engine/gservices_settings.h b/google_apis/gcm/engine/gservices_settings.h
index db3c6b0fa77ef24f3bfb39fc591812b37eb8ce92..775c676fa32e86716d727bee53eaf962c8576123 100644
--- a/google_apis/gcm/engine/gservices_settings.h
+++ b/google_apis/gcm/engine/gservices_settings.h
@@ -19,6 +19,9 @@ namespace gcm {
 // extracting them from checkin response and storing in GCMStore.
 class GCM_EXPORT GServicesSettings {
  public:
+  // Minimum periodic checkin interval in seconds.
+  static const int64 kMinimumCheckinInterval;
+
   // Create an instance of GServicesSettings class. |gcm_store| is used to store
   // the settings after they are extracted from checkin response.
   explicit GServicesSettings(GCMStore* gcm_store);