Report usage of StopAutoUpdate policy in borgmon charts

Omaha already has an event result for reporting UpdateDeferred (9)
which shows up in the borgman charts. In order to use that we should
perform a normal updatecheck without the updatedisabled set to true and
then discard the response with event type UpdateComplete (3) but with
event result UpdateDeferred (9).

BUG=28645: Report StopAutoUpdate enforcement in Borgmon charts for Omaha
TEST=Tested success, error and deferred cases on my zgb.
Change-Id: I27cb4465ea9876b39edaff3b747ada44a4f875d4
Reviewed-on: https://gerrit.chromium.org/gerrit/19112
Reviewed-by: Don Garrett <dgarrett@chromium.org>
Commit-Ready: Jay Srinivasan <jaysri@chromium.org>
Tested-by: Jay Srinivasan <jaysri@chromium.org>
diff --git a/omaha_request_action.h b/omaha_request_action.h
index b32a3af..b3df207 100644
--- a/omaha_request_action.h
+++ b/omaha_request_action.h
@@ -57,6 +57,7 @@
 // complete list of defined event types and results, see
 // http://code.google.com/p/omaha/wiki/ServerProtocol#event
 struct OmahaEvent {
+  // The Type values correspond to EVENT_TYPE values of Omaha.
   enum Type {
     kTypeUnknown = 0,
     kTypeDownloadComplete = 1,
@@ -66,10 +67,12 @@
     kTypeUpdateDownloadFinished = 14,
   };
 
+  // The Result values correspond to EVENT_RESULT values of Omaha.
   enum Result {
     kResultError = 0,
     kResultSuccess = 1,
     kResultSuccessReboot = 2,
+    kResultUpdateDeferred = 9, // When we ignore/defer updates due to policy.
   };
 
   OmahaEvent()