ServiceWorker: Store registration data in ServiceWorkerDatabase

content/browser/service_worker/service_worker_database.proto

+// Copyright 2014 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.
+
+syntax = "proto2";
+
+option optimize_for = LITE_RUNTIME;
+
+package content;
+
+message ServiceWorkerRegistrationData {
+  required int64 registration_id = 1;
+  required string scope_url = 2;
+  required string script_url = 3;
+
+  // Versions are first stored once they successfully install and become the
+  // waiting version. Then they are updated when they transition to the active
+  // version.
+  required int64 version_id = 5;
+
+  optional bool is_active = 6;
+  optional bool has_fetch_handler = 7;
+
+  // Serialized by Time::ToInternalValue().
+  optional int64 last_update_check_time = 8;
+}
+
+message ServiceWorkerResourceRecord {
+  required int64 resource_id = 1;
+  optional string url = 2;

[michaeln, 2014/04/24 00:35:04]

since this is the first cut at it (and there is no version skew stuff), can we
make all fields 'required' in both classes

[nhiroki, 2014/04/24 05:57:30]

Hmm... if we mark them as required,
- need to set all fields in unittests. I think that would be a bit messy.
- cannot ignore deprecated fields in future versions, that is, we need to set
them to dummy value even if they are no longer used.

so I'd prefer to leave them. Wdyt?

+}