Introduce the plumbing necessary to report Unrecoverable error from model safe workers.

chrome/browser/sync/engine/model_changing_syncer_command.cc

Index: chrome/browser/sync/engine/model_changing_syncer_command.cc
diff --git a/chrome/browser/sync/engine/model_changing_syncer_command.cc b/chrome/browser/sync/engine/model_changing_syncer_command.cc
index 797f795f96bd08580aeb6ac466459e231e7c7763..c431073e7545f9dafb605e51a3920e612f6dc444 100644
--- a/chrome/browser/sync/engine/model_changing_syncer_command.cc
+++ b/chrome/browser/sync/engine/model_changing_syncer_command.cc
@@ -48,6 +48,16 @@ void ModelChangingSyncerCommand::ExecuteImpl(sessions::SyncSession* session) {
     scoped_ptr<Callback0::Type> c(NewCallback(this,
         &ModelChangingSyncerCommand::StartChangingModel));
     worker->DoWorkAndWaitUntilDone(c.get());
+
+    if (session->unrecoverable_error()) {

[akalin, 2011/10/21 22:18:27]

Why not just make the (optional) unrecoverable error a return value of
DoWorkAndWaitUntilDone?

Then, why not make that error a return value of ExecuteImpl and have the syncer
check it, then propagate up to the SyncScheduler, etc.?

[lipalani1, 2011/10/21 23:40:03]

Agreed
On 2011/10/21 22:18:27, akalin wrote:

+      // We are back on the syncer thread. Now use the delegate to send the
+      // error.
+      DCHECK(session->unrecoverable_error_info());
+      session->delegate()->OnUnrecoverableError(
+          session->unrecoverable_error_info()->location,
+          session->unrecoverable_error_info()->message);
+      break;
+    }
   }
 }