Switch to mojo localstorage backend by default.

content/browser/dom_storage/dom_storage_context_wrapper.h

Index: content/browser/dom_storage/dom_storage_context_wrapper.h
diff --git a/content/browser/dom_storage/dom_storage_context_wrapper.h b/content/browser/dom_storage/dom_storage_context_wrapper.h
index c8945c24e066cab7ab558f2aff3e340677b5920c..4eef34a6335f357e6f2d77664a9783675ddd49a6 100644
--- a/content/browser/dom_storage/dom_storage_context_wrapper.h
+++ b/content/browser/dom_storage/dom_storage_context_wrapper.h
@@ -77,6 +77,9 @@ class CONTENT_EXPORT DOMStorageContextWrapper :
   void OpenLocalStorage(const url::Origin& origin,
                         mojom::LevelDBWrapperRequest request);
 
+  leveldb::mojom::LevelDBDatabaseAssociatedRequest
+  LocalStorageDatabaseRequestForTesting();
+
  private:
   friend class DOMStorageMessageFilter;  // for access to context()
   friend class SessionStorageNamespaceImpl;  // ditto