AU: Include a bit flag (bit 31) in error codes to indicate non-normal boot mode.

BUG=chromium-os:10320
TEST=unit test, tested on device in normal and dev mode

Change-Id: I67d695bc167a4cc1a638711f047e2b86f8eaa8f1

Review URL: http://codereview.chromium.org/6098008
diff --git a/action_processor.h b/action_processor.h
index 0cf6ff6..124fe00 100644
--- a/action_processor.h
+++ b/action_processor.h
@@ -46,6 +46,9 @@
   kActionCodeOmahaRequestNoUpdateCheckStatus = 203,
   kActionCodeOmahaRequestBadUpdateCheckStatus = 204,
   kActionCodeOmahaRequestHTTPResponseBase = 2000,  // + HTTP response code
+
+  // Bit flags.
+  kActionCodeBootModeFlag = 1 << 31,  // Set if boot mode not normal.
 };
 
 class AbstractAction;