AU: Separate error codes for different OmahaRequestAction failures.

BUG=8651
TEST=unit tests, tested an update on the device through dev server

Change-Id: Ic590906be269fe371702bfbe282cddc197ab01fc

Review URL: http://codereview.chromium.org/4432002
diff --git a/action_processor.h b/action_processor.h
index 9bc4ef2..2618c39 100644
--- a/action_processor.h
+++ b/action_processor.h
@@ -38,6 +38,12 @@
   kActionCodeDownloadPayloadVerificationError = 12,
   kActionCodeDownloadAppliedUpdateVerificationError = 13,
   kActionCodeDownloadWriteError = 14,
+  kActionCodeOmahaRequestEmptyResponseError = 200,
+  kActionCodeOmahaRequestXMLParseError = 201,
+  kActionCodeOmahaRequestNoUpdateCheckNode = 202,
+  kActionCodeOmahaRequestNoUpdateCheckStatus = 203,
+  kActionCodeOmahaRequestBadUpdateCheckStatus = 204,
+  kActionCodeOmahaRequestHTTPResponseBase = 2000,  // + HTTP response code
 };
 
 class AbstractAction;