Keep the GCM data intact when the user signs out of the profile

chrome/browser/services/gcm/gcm_profile_service.cc

Index: chrome/browser/services/gcm/gcm_profile_service.cc
diff --git a/chrome/browser/services/gcm/gcm_profile_service.cc b/chrome/browser/services/gcm/gcm_profile_service.cc
index 7ade721b45bae41c2b438138bdba77d2bbd62ffe..0349d5493a7ccaec7653285a29566143204ee532 100644
--- a/chrome/browser/services/gcm/gcm_profile_service.cc
+++ b/chrome/browser/services/gcm/gcm_profile_service.cc
@@ -120,9 +120,11 @@ void GCMProfileService::IdentityObserver::OnActiveAccountLogout() {
   // Check is necessary to not crash browser_tests.
   if (gcm_account_tracker_)
     gcm_account_tracker_->Stop();
-  // TODO(fgorski): If we purge here, what should happen when we get
-  // OnActiveAccountLogin() right after that?
-  driver_->Purge();
+  // When sign-in enforcement is not dropped, OnSignedOut will also clear all
+  // the GCM data and a new GCM ID will be retrieved after the user signs in
+  // again. Otherwise, the user sign-out will not affect the existing GCM
+  // data.
+  driver_->OnSignedOut();
 }
 
 std::string GCMProfileService::IdentityObserver::SignedInUserName() const {