Add an action for server to send down rollback command.

sync/protocol/sync_protocol_error.h

Index: sync/protocol/sync_protocol_error.h
diff --git a/sync/protocol/sync_protocol_error.h b/sync/protocol/sync_protocol_error.h
index be9232d21989f4dbd6469f7c1c41b002d21a2cb2..f59d191246e624b109344ae86eb5814cbcc3a4ca 100644
--- a/sync/protocol/sync_protocol_error.h
+++ b/sync/protocol/sync_protocol_error.h
@@ -42,6 +42,9 @@ enum SyncProtocolErrorType {
   // An administrator disabled sync for this domain.
   DISABLED_BY_ADMIN,
 
+  // User asked to stop syncing this device and roll back local data.
+  USER_ROLLBACK,

[maniscalco, 2014/04/17 18:05:29]

Should you also update the switch statement in
GetClientToServerResponseErrorType from
chrome/browser/sync/test/integration/sync_test.cc ?

Seems like GetClientToServerResponseErrorType probably belongs in a more central
location (like syncer_proto_util.cc?) so it will be more likely to get updated
in the future.

[haitaol1, 2014/04/17 18:51:40]

The new enum is missed because switch in GetClientToServerResponseErrorType()
has a default case. After removing that, compiler starts complaining missing
handling of enums. I removed the default case and handled all enums explcitly.

On 2014/04/17 18:05:29, maniscalco wrote:

[maniscalco, 2014/04/18 16:29:15]

Good idea.

On 2014/04/17 18:51:40, haitaol1 wrote:

+
   // The default value.
   UNKNOWN_ERROR
 };
@@ -66,6 +69,9 @@ enum ClientAction {
   // settings page that account is disabled.
   STOP_SYNC_FOR_DISABLED_ACCOUNT,
 
+  // Disable sync and roll back local model to pre-sync state.
+  DISABLE_SYNC_AND_ROLLBACK,

[maniscalco, 2014/04/17 18:05:29]

Similar to my other comment about updating the switch statement in sync_test.cc,
do you need to update ClientAction switch statements?  E.g. the one in
GetClientActionString from sync_protocol_error.cc ?

[haitaol1, 2014/04/17 18:51:40]

Done.

+
   // The default. No action.
   UNKNOWN_ACTION
 };