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

chrome/browser/sync/engine/sync_scheduler.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/sync/engine/sync_scheduler.h"
 
 #include <algorithm>
 #include <cstring>
 
 #include "base/bind.h"
@@ skipping 1147 matching lines @@
     const sessions::SyncSessionSnapshot& snapshot) {
   DCHECK_EQ(MessageLoop::current(), sync_loop_);
   if (ShouldRequestEarlyExit(snapshot.errors.sync_protocol_error)) {
     SVLOG(2) << "Sync Scheduler requesting early exit.";
     syncer_->RequestEarlyExit();  // Thread-safe.
   }
   if (IsActionableError(snapshot.errors.sync_protocol_error))
     OnActionableError(snapshot);
 }
 
+void SyncScheduler::OnUnrecoverableError(
+    const tracked_objects::Location& from_here,
+    const std :: string& message) {
+  syncer_->RequestEarlyExit();
+  SyncEngineEvent event(from_here, message);
+  session_context_->NotifyListeners(event);
+}
 
 void SyncScheduler::OnServerConnectionEvent(
     const ServerConnectionEvent& event) {
   DCHECK_EQ(MessageLoop::current(), sync_loop_);
   PostTask(FROM_HERE, "CheckServerConnectionManagerStatus",
            base::Bind(&SyncScheduler::CheckServerConnectionManagerStatus,
                       weak_ptr_factory_.GetWeakPtr(),
                       event.connection_code));
 }
 
 void SyncScheduler::set_notifications_enabled(bool notifications_enabled) {
   DCHECK_EQ(MessageLoop::current(), sync_loop_);
   session_context_->set_notifications_enabled(notifications_enabled);
 }
 
 base::TimeDelta SyncScheduler::sessions_commit_delay() const {
   DCHECK_EQ(MessageLoop::current(), sync_loop_);
   return sessions_commit_delay_;
 }
 
 #undef SVLOG_LOC
 
 #undef SVLOG
 
 #undef SLOG
 
 #undef ENUM_CASE
 
 }  // browser_sync