Fix one case that can make sync backend stuck in auth error state.

In case like server outage/bug, sync backend can receive same invalid
token in a row and stay in auth error state without frontend knowing
it. This change makes backend report auth error again if this happens.
Frontend will request token again but also use exponetial backoff to
protect againest hammering token server too often.

BUG=311420

Review URL: https://codereview.chromium.org/62423002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233938 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 13 insertions, 1 deletions

diff --git a/sync/engine/net/server_connection_manager.cc b/sync/engine/net/server_connection_manager.cc
index d668869..2cb7810 100644
--- a/sync/engine/net/server_connection_manager.cc
+++ b/sync/engine/net/server_connection_manager.cc
@@ -233,6 +233,14 @@ bool ServerConnectionManager::SetAuthToken(const std::string& auth_token) {
     previously_invalidated_token = std::string();
     return true;
   }
+
+  // This could happen in case like server outage/bug. E.g. token returned by
+  // first request is considered invalid by sync server and because
+  // of token server's caching policy, etc, same token is returned on second
+  // request. Need to notify sync frontend again to request new token,
+  // otherwise backend will stay in SYNC_AUTH_ERROR state while frontend thinks
+  // everything is fine and takes no actions.
+  SetServerStatus(HttpResponse::SYNC_AUTH_ERROR);
   return false;
 }
 
@@ -252,8 +260,12 @@ void ServerConnectionManager::InvalidateAndClearAuthToken() {
 
 void ServerConnectionManager::SetServerStatus(
     HttpResponse::ServerConnectionCode server_status) {
-  if (server_status_ == server_status)
+  // SYNC_AUTH_ERROR is permanent error. Need to notify observer to take
+  // action externally to resolve.
+  if (server_status != HttpResponse::SYNC_AUTH_ERROR &&
+      server_status_ == server_status) {
     return;
+  }
   server_status_ = server_status;
   NotifyStatusChanged();
 }