Add base persistence interfaces for Prefetching Offline Pages.

components/offline_pages/core/prefetch/prefetch_item.cc

Index: components/offline_pages/core/prefetch/prefetch_item.cc
diff --git a/components/offline_pages/core/prefetch/prefetch_item.cc b/components/offline_pages/core/prefetch/prefetch_item.cc
new file mode 100644
index 0000000000000000000000000000000000000000..8e1119d4f694ed90e7f1d0126d37a5ed423b1bd8
--- /dev/null
+++ b/components/offline_pages/core/prefetch/prefetch_item.cc
@@ -0,0 +1,32 @@
+// Copyright 2017 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 "components/offline_pages/core/prefetch/prefetch_item.h"
+
+namespace offline_pages {
+
+PrefetchItem::PrefetchItem() = default;
+
+PrefetchItem::PrefetchItem(const PrefetchItem& other) = default;
+
+PrefetchItem::~PrefetchItem(){};
+
+bool PrefetchItem::operator==(const PrefetchItem& other) const {
+  return guid == other.guid && client_name_space == other.client_name_space &&
+         client_id == other.client_id && state == other.state &&
+         url == other.url && final_archived_url == other.final_archived_url &&
+         request_archive_attempt_count == other.request_archive_attempt_count &&
+         operation_name == other.operation_name &&
+         archive_body_name == other.archive_body_name &&
+         archive_body_length == other.archive_body_length &&
+         creation_time == other.creation_time &&
+         freshness_time == other.freshness_time &&
+         error_code == other.error_code;
+}
+
+bool PrefetchItem::operator!=(const PrefetchItem& other) const {
+  return !(*this == other);
+}
+
+}  // namespace offline_pages