AU: send success events to Omaha at more points in the update process.

BUG=560
TEST=unit tests, gmerged on device and looked at logs, emerge-arm-generic.

Review URL: http://codereview.chromium.org/3044003
diff --git a/omaha_request_action.h b/omaha_request_action.h
index 307798b..5564e73 100644
--- a/omaha_request_action.h
+++ b/omaha_request_action.h
@@ -55,6 +55,8 @@
     kTypeDownloadComplete = 1,
     kTypeInstallComplete = 2,
     kTypeUpdateComplete = 3,
+    kTypeUpdateDownloadStarted = 13,
+    kTypeUpdateDownloadFinished = 14,
   };
 
   enum Result {