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

chrome/browser/sync/internal_api/debug_info_event_listener.cc

Index: chrome/browser/sync/internal_api/debug_info_event_listener.cc
diff --git a/chrome/browser/sync/internal_api/debug_info_event_listener.cc b/chrome/browser/sync/internal_api/debug_info_event_listener.cc
index 3165496331d3c76549036d0d77554b202f079ff5..f9914d05c3987f7321c1cf87721aa7e65b0bf2b7 100644
--- a/chrome/browser/sync/internal_api/debug_info_event_listener.cc
+++ b/chrome/browser/sync/internal_api/debug_info_event_listener.cc
@@ -97,6 +97,14 @@ void DebugInfoEventListener::GetAndClearDebugInfo(
   events_dropped_ = false;
 }
 
+void DebugInfoEventListener::OnUnrecoverableError(
+    const tracked_objects::Location& location,
+    const std::string& message) {
+  // Nothing to log.
+  return;
+}
+
+
 void DebugInfoEventListener::CreateAndAddEvent(
     sync_pb::DebugEventInfo::EventType type) {
   sync_pb::DebugEventInfo event_info;