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

chrome/browser/sync/sessions/unrecoverable_error_info.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/sessions/unrecoverable_error_info.h"
+namespace browser_sync {
+namespace sessions {
+
+UnrecoverableErrorInfo::UnrecoverableErrorInfo()
+    : set_(false) {
+}
+
+UnrecoverableErrorInfo::UnrecoverableErrorInfo(
+    const tracked_objects::Location& location,
+    const std::string& message)
+    : location_(location),
+      message_(message),
+      set_(true) {
+}
+
+UnrecoverableErrorInfo::~UnrecoverableErrorInfo() {
+}
+
+void UnrecoverableErrorInfo::Set(
+    const tracked_objects::Location& location,
+    const std::string& message) {
+  DCHECK(IsSet() == false);

[akalin, 2011/10/25 03:20:06]

i think it's fine to allow resetting, i.e. this DCHECK isn't needed

[lipalani1, 2011/10/26 00:12:13]

Done.

+  location_ = location;
+  message_ = message;
+  set_ = true;
+}
+
+bool UnrecoverableErrorInfo::IsSet() const {
+  return set_;
+}
+
+const tracked_objects::Location& UnrecoverableErrorInfo::location() const {
+  DCHECK(set_);
+  return location_;
+}
+
+const std::string& UnrecoverableErrorInfo::message() const {

[akalin, 2011/10/25 03:20:06]

DCHECK(set_) here, too

[lipalani1, 2011/10/26 00:12:13]

Done.

+  return message_;
+}
+
+}  // namespace sessions
+}  // namespace browser_sync