MAGETWO-66318: Remove usages of serialize/unserialize in CmsSampleData

- fix build failures

Author: Joan He

app/code/Magento/CatalogWidget/Test/Unit/Block/Product/ProductsListTest.php

@@ -97,11 +97,9 @@ protected function setUp()
         $this->builder = $this->getMock(\Magento\Rule\Model\Condition\Sql\Builder::class, [], [], '', false);
         $this->rule = $this->getMock(\Magento\CatalogWidget\Model\Rule::class, [], [], '', false);
         $this->serializer = $this->getMock(\Magento\Framework\Serialize\Serializer\Json::class, [], [], '', false);
-        $this->widgetConditionsHelper = $this->getMock(
-            \Magento\Widget\Helper\Conditions::class,
-            [],
-            ['serializer' => $this->serializer]
-        );
+        $this->widgetConditionsHelper = $this->getMockBuilder(\Magento\Widget\Helper\Conditions::class)
+            ->disableOriginalConstructor()
+            ->getMock();
         $this->storeManager = $this->getMock(\Magento\Store\Model\StoreManagerInterface::class);
         $this->design = $this->getMock(\Magento\Framework\View\DesignInterface::class);
 

app/code/Magento/Widget/Setup/LayoutUpdateConverter.php

@@ -21,6 +21,13 @@ class LayoutUpdateConverter extends SerializedToJson
      */
     private $normalizer;
 
+    /**
+     * LayoutUpdateConverter constructor.
+     *
+     * @param Serialize $serialize
+     * @param Json $json
+     * @param Normalizer $normalizer
+     */
     public function __construct(
         Serialize $serialize,
         Json $json,