AU: Send a previous version event after reboot following an update.
The previous version event is sent along with the first update check. This is
best effort -- if the update check doesn't reach the server, the event is lost.
BUG=9198
TEST=unit tests, tested on device
Change-Id: I5ceb7c8e99ae54eb331f6ac58b8977d2a111461c
Review URL: http://codereview.chromium.org/5993007
diff --git a/prefs_interface.h b/prefs_interface.h
index 81aa770..8d07dde 100644
--- a/prefs_interface.h
+++ b/prefs_interface.h
@@ -13,6 +13,7 @@
extern const char kPrefsLastActivePingDay[];
extern const char kPrefsLastRollCallPingDay[];
extern const char kPrefsManifestMetadataSize[];
+extern const char kPrefsPreviousVersion[];
extern const char kPrefsResumedUpdateFailures[];
extern const char kPrefsUpdateCheckResponseHash[];
extern const char kPrefsUpdateStateNextDataOffset[];