[js-tests] prevent frequently click 'Main Menu' button, load main scene multiple times (cocos2d#19228)

Author: PatriceJiang

tests/js-tests/src/tests-main.js

@@ -45,6 +45,7 @@ var autoTestEnabled = autoTestEnabled || false;
 var autoTestCurrentTestName = autoTestCurrentTestName || "N/A";
 
 var TestScene = cc.Scene.extend({
+    _mainMenu :null, 
     ctor:function (bPortrait) {
         this._super();
         this.init();
@@ -53,6 +54,7 @@ var TestScene = cc.Scene.extend({
         var menuItem = new cc.MenuItemLabel(label, this.onMainMenuCallback, this);
 
         var menu = new cc.Menu(menuItem);
+        this._mainMenu = menu;
         menu.x = 0;
         menu.y = 0;
         menuItem.x = winSize.width - 50;
@@ -66,6 +68,7 @@ var TestScene = cc.Scene.extend({
         if (director.isPaused()) {
             director.resume();
         } 
+        this._mainMenu.enabled = false;
         var scene = new cc.Scene();
         var layer = new TestController();
         scene.addChild(layer);