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

chrome/browser/sync/glue/password_model_worker.h

Index: chrome/browser/sync/glue/password_model_worker.h
diff --git a/chrome/browser/sync/glue/password_model_worker.h b/chrome/browser/sync/glue/password_model_worker.h
index 8aa4956f2883b4b38ac83b499678968c2de74281..317e3a54117bf58d26f808b37cacc3946b21dc11 100644
--- a/chrome/browser/sync/glue/password_model_worker.h
+++ b/chrome/browser/sync/glue/password_model_worker.h
@@ -7,6 +7,7 @@
 #pragma once
 
 #include "chrome/browser/sync/engine/model_safe_worker.h"
+#include "chrome/browser/sync/sessions/unrecoverable_error_info.h"
 
 #include "base/basictypes.h"
 #include "base/callback.h"
@@ -29,12 +30,15 @@ class PasswordModelWorker : public browser_sync::ModelSafeWorker {
   virtual ~PasswordModelWorker();
 
   // ModelSafeWorker implementation. Called on syncapi SyncerThread.
-  virtual void DoWorkAndWaitUntilDone(Callback0::Type* work);
+  virtual sessions::UnrecoverableErrorInfo DoWorkAndWaitUntilDone(
+      Callback1<sessions::UnrecoverableErrorInfo*>::Type* work) OVERRIDE;
   virtual ModelSafeGroup GetModelSafeGroup();
 
  private:
-  void CallDoWorkAndSignalTask(Callback0::Type* work,
-                               base::WaitableEvent* done);
+  void CallDoWorkAndSignalTask(
+    Callback1<sessions::UnrecoverableErrorInfo*>::Type* work,
+    base::WaitableEvent* done,
+    sessions::UnrecoverableErrorInfo* error_info);
 
   scoped_refptr<PasswordStore> password_store_;
   DISALLOW_COPY_AND_ASSIGN(PasswordModelWorker);