Add command line overrides for GCM checkin URL & MCS endpoint

google_apis/gcm/engine/gservices_switches.cc

Index: google_apis/gcm/engine/gservices_switches.cc
diff --git a/google_apis/gcm/engine/gservices_switches.cc b/google_apis/gcm/engine/gservices_switches.cc
index 66c910ff2cb995bf30c1edaf6e8dd6ffdf48900b..efa5555e4673f1d53669432336f173847b30ec60 100644
--- a/google_apis/gcm/engine/gservices_switches.cc
+++ b/google_apis/gcm/engine/gservices_switches.cc
@@ -6,6 +6,14 @@
 
 namespace switches {
 
+// Sets the checkin service endpoint that will be used for performing Google
+// Cloud Messaging checkins.
+const char kGCMCheckinURL[] = "gcm-checkin-url";
+
+// Sets the Mobile Connection Server endpoint that will be used for Google
+// Cloud Messaging.
+const char kGCMMCSEndpoint[] = "gcm-mcs-endpoint";
+
 // Sets the registration endpoint that will be used for creating new Google
 // Cloud Messaging registrations.
 const char kGCMRegistrationURL[] = "gcm-registration-url";