ServiceWorker: Migrate the script cache backend from BlockFile to Simple

content/browser/service_worker/service_worker_database.h

Index: content/browser/service_worker/service_worker_database.h
diff --git a/content/browser/service_worker/service_worker_database.h b/content/browser/service_worker/service_worker_database.h
index a43521239015e3c4e90700a83440c843d8167e16..cbc417fab64663b5426a0e2fec350b57594e19e6 100644
--- a/content/browser/service_worker/service_worker_database.h
+++ b/content/browser/service_worker/service_worker_database.h
@@ -92,6 +92,16 @@ class CONTENT_EXPORT ServiceWorkerDatabase {
       int64* next_avail_version_id,
       int64* next_avail_resource_id);
 
+  // Used for diskcache migration (http://crbug.com/487482). Returns true if the
+  // storage needs to migrate a disk cache.
+  Status IsDiskCacheMigrationNeeded(bool* migration_needed);
+  Status SetDiskCacheMigrationNotNeeded();
+
+  // Used for diskcache migration (http://crbug.com/487482). Returns true if the
+  // storage needs to delete an old disk cache.
+  Status IsOldDiskCacheDeletionNeeded(bool* deletion_needed);
+  Status SetOldDiskCacheDeletionNotNeeded();
+
   // Reads origins that have one or more than one registration from the
   // database. Returns OK if they are successfully read or not found.
   // Otherwise, returns an error.
@@ -366,6 +376,13 @@ class CONTENT_EXPORT ServiceWorkerDatabase {
   };
   State state_;
 
+#if defined(UNIT_TEST)
+  void set_skip_writing_diskcache_migration_state_on_init() {

[falken, 2015/06/16 04:28:10]

nit: can you add "_for_testing" to the function and variable names?

[nhiroki, 2015/06/16 07:12:15]

Done.

+    skip_writing_diskcache_migration_state_on_init_ = true;
+  };
+#endif
+  bool skip_writing_diskcache_migration_state_on_init_;
+
   base::SequenceChecker sequence_checker_;
 
   FRIEND_TEST_ALL_PREFIXES(ServiceWorkerDatabaseTest, OpenDatabase);
@@ -377,7 +394,12 @@ class CONTENT_EXPORT ServiceWorkerDatabase {
   FRIEND_TEST_ALL_PREFIXES(ServiceWorkerDatabaseTest,
                            UserData_UninitializedDatabase);
   FRIEND_TEST_ALL_PREFIXES(ServiceWorkerDatabaseTest, DestroyDatabase);
+  FRIEND_TEST_ALL_PREFIXES(ServiceWorkerDatabaseTest, DiskCacheMigrationState);
   FRIEND_TEST_ALL_PREFIXES(ServiceWorkerDatabaseTest, UpgradeSchemaToVersion2);
+  FRIEND_TEST_ALL_PREFIXES(ServiceWorkerDiskCacheMigratorTest,
+                           MigrateOnDiskCacheAccess);
+  FRIEND_TEST_ALL_PREFIXES(ServiceWorkerDiskCacheMigratorTest,
+                           NotMigrateOnDatabaseAccess);
 
   DISALLOW_COPY_AND_ASSIGN(ServiceWorkerDatabase);
 };