AU: Fall back to full updates after a number of failed delta update attempts.
Count each failed delta update attempt. Keep the count in persistent storage. If
the count exceeds a threshold (3), disable delta updates by setting delta_okay
to false in the update check request.
Once this CL is in, we have to ensure that we have a full update payload
available on the update server for each version otherwise we may orphan clients.
BUG=7221
TEST=unit tests, gmerged on device and tested with a mod'ed dev server
Change-Id: I7f7fa73f652f12f22cc8604dad6a26c802b8582d
Review URL: http://codereview.chromium.org/3617002
diff --git a/prefs_interface.h b/prefs_interface.h
index dbfa68a..724651e 100644
--- a/prefs_interface.h
+++ b/prefs_interface.h
@@ -9,6 +9,7 @@
namespace chromeos_update_engine {
+extern const char kPrefsDeltaUpdateFailures[];
extern const char kPrefsLastActivePingDay[];
extern const char kPrefsLastRollCallPingDay[];