Expose durable storage to workers.

Source/modules/quota/WorkerNavigatorStorageQuota.idl

Index: Source/modules/quota/WorkerNavigatorStorageQuota.idl
diff --git a/Source/modules/quota/WorkerNavigatorStorageQuota.idl b/Source/modules/quota/WorkerNavigatorStorageQuota.idl
index c47cb53610a66eac60e85626ddc78f164a6be8ae..cb14bb6c7c471eb7639911c41df9d54b571d76e5 100644
--- a/Source/modules/quota/WorkerNavigatorStorageQuota.idl
+++ b/Source/modules/quota/WorkerNavigatorStorageQuota.idl
@@ -17,7 +17,13 @@
  * Boston, MA 02110-1301, USA.
  */
 
+// This partial interface is a merge of two different partial interfaces
+// related to storage.
 partial interface WorkerNavigator {
+    // http://www.w3.org/TR/2012/WD-quota-api-20120703/#idl-def-StorageQuotaEnvironment
     [MeasureAs=PrefixedStorageQuota] readonly attribute DeprecatedStorageQuota webkitTemporaryStorage;
     [MeasureAs=PrefixedStorageQuota] readonly attribute DeprecatedStorageQuota webkitPersistentStorage;
+
+    // https://storage.spec.whatwg.org/#api
+    [RuntimeEnabled=DurableStorage] readonly attribute StorageManager storage;
 };