From 383f1d9bac87c2cc85eb3457981ecf7a13c65221 Mon Sep 17 00:00:00 2001
From: Tianwei Du <duzc2dtw@gmail.com>
Date: Sat, 9 Dec 2017 02:49:35 +0800
Subject: [PATCH] Develop (#1501)

Adds missing requires in core/extensions
---
 core/extensions.js | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/core/extensions.js b/core/extensions.js
index b6f4a25c2..1ce582cc1 100644
--- a/core/extensions.js
+++ b/core/extensions.js
@@ -33,6 +33,9 @@
  **/
 goog.provide('Blockly.Extensions');
 
+goog.require('Blockly.Mutator');
+goog.require('Blockly.utils');
+goog.require('goog.string');
 
 /**
  * The set of all registered extensions, keyed by extension name/id.