Service Worker: Migrate to version_uuid and surface ServiceWorker.id. (Chromium 2/3)

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 = 4;
+  required string version_uuid = 4;
 
   required bool is_active = 5;
   required bool has_fetch_handler = 6;
 
   // Serialized by Time::ToInternalValue().
   required int64 last_update_check_time = 7;
 
   optional uint64 resources_total_size_bytes = 8;
 }
 
 message ServiceWorkerResourceRecord {
   required int64 resource_id = 1;
   required string url = 2;
   optional uint64 size_bytes = 3;
 }